diff --git a/.github/workflows/colcon.yml b/.github/workflows/colcon.yml
index e35c782c0c..4d59e04062 100644
--- a/.github/workflows/colcon.yml
+++ b/.github/workflows/colcon.yml
@@ -156,7 +156,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/cygwin_build.yml b/.github/workflows/cygwin_build.yml
index 36a76dd1d6..1cf7932a1a 100644
--- a/.github/workflows/cygwin_build.yml
+++ b/.github/workflows/cygwin_build.yml
@@ -177,7 +177,7 @@ jobs:
           source ~/ccache.conf &&
           ccache -s
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: D:/a/ardupilot/ardupilot/ccache
           key: ${{ steps.ccache_cache_timestamp.outputs.cache-key }}-ccache-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/macos_build.yml b/.github/workflows/macos_build.yml
index 0ad9e37f55..bfa7010904 100644
--- a/.github/workflows/macos_build.yml
+++ b/.github/workflows/macos_build.yml
@@ -169,7 +169,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{matrix.config}}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_chibios.yml b/.github/workflows/test_chibios.yml
index ff865d9e11..22c9761003 100644
--- a/.github/workflows/test_chibios.yml
+++ b/.github/workflows/test_chibios.yml
@@ -182,7 +182,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{matrix.config}}-${{ matrix.toolchain }}-${{ matrix.gcc }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_coverage.yml b/.github/workflows/test_coverage.yml
index c6dba24a39..150159b4c3 100644
--- a/.github/workflows/test_coverage.yml
+++ b/.github/workflows/test_coverage.yml
@@ -48,7 +48,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_dds.yml b/.github/workflows/test_dds.yml
index 22fa60653b..9001de83a5 100644
--- a/.github/workflows/test_dds.yml
+++ b/.github/workflows/test_dds.yml
@@ -161,7 +161,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.config }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_linux_sbc.yml b/.github/workflows/test_linux_sbc.yml
index 6e69b7362c..2bec49b8ba 100644
--- a/.github/workflows/test_linux_sbc.yml
+++ b/.github/workflows/test_linux_sbc.yml
@@ -181,7 +181,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{matrix.config}}-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_replay.yml b/.github/workflows/test_replay.yml
index 99dfa7c97b..7799d0317a 100644
--- a/.github/workflows/test_replay.yml
+++ b/.github/workflows/test_replay.yml
@@ -170,7 +170,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_sitl_blimp.yml b/.github/workflows/test_sitl_blimp.yml
index 1d592fedb8..7d9e55e51b 100644
--- a/.github/workflows/test_sitl_blimp.yml
+++ b/.github/workflows/test_sitl_blimp.yml
@@ -182,7 +182,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_sitl_copter.yml b/.github/workflows/test_sitl_copter.yml
index e5712fec1b..07efd7f4d1 100644
--- a/.github/workflows/test_sitl_copter.yml
+++ b/.github/workflows/test_sitl_copter.yml
@@ -181,7 +181,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
@@ -302,7 +302,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-base-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_sitl_periph.yml b/.github/workflows/test_sitl_periph.yml
index 63d65bb5b5..de470a8e09 100644
--- a/.github/workflows/test_sitl_periph.yml
+++ b/.github/workflows/test_sitl_periph.yml
@@ -172,7 +172,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{steps.ccache_cache_timestamp.outputs.timestamp}}
@@ -222,7 +222,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_sitl_plane.yml b/.github/workflows/test_sitl_plane.yml
index 34c112e59b..813560a941 100644
--- a/.github/workflows/test_sitl_plane.yml
+++ b/.github/workflows/test_sitl_plane.yml
@@ -181,7 +181,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_sitl_rover.yml b/.github/workflows/test_sitl_rover.yml
index d13185aca1..3c29c931be 100644
--- a/.github/workflows/test_sitl_rover.yml
+++ b/.github/workflows/test_sitl_rover.yml
@@ -180,7 +180,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_sitl_sub.yml b/.github/workflows/test_sitl_sub.yml
index 958787a29b..0a8555c114 100644
--- a/.github/workflows/test_sitl_sub.yml
+++ b/.github/workflows/test_sitl_sub.yml
@@ -184,7 +184,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_sitl_tracker.yml b/.github/workflows/test_sitl_tracker.yml
index 7708647b92..518d648b7f 100644
--- a/.github/workflows/test_sitl_tracker.yml
+++ b/.github/workflows/test_sitl_tracker.yml
@@ -183,7 +183,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_size.yml b/.github/workflows/test_size.yml
index c4be1bc064..30e7f4bba2 100644
--- a/.github/workflows/test_size.yml
+++ b/.github/workflows/test_size.yml
@@ -97,7 +97,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}
diff --git a/.github/workflows/test_unit_tests.yml b/.github/workflows/test_unit_tests.yml
index 3d94ad2db1..bc325afb7d 100644
--- a/.github/workflows/test_unit_tests.yml
+++ b/.github/workflows/test_unit_tests.yml
@@ -126,7 +126,7 @@ jobs:
           NOW=$(date -u +"%F-%T")
           echo "timestamp=${NOW}" >> $GITHUB_OUTPUT
       - name: ccache cache files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.ccache
           key: ${{github.workflow}}-ccache-${{ matrix.toolchain }}-${{steps.ccache_cache_timestamp.outputs.timestamp}}