github: test mantic not bionic

bionic no longer builds  SITL:
../../libraries/AP_Logger/AP_Logger_Backend.cpp: In member function 'bool AP_Logger_Backend::Write_VER()':
../../libraries/AP_Logger/AP_Logger_Backend.cpp:577:5: sorry, unimplemented: non-trivial designated initializers not supported
     };
     ^
compilation terminated due to -Wfatal-errors.

.github/workflows/test_environment.yml

@@ -28,14 +28,14 @@ jobs:
       fail-fast: false  # don't cancel if a job from the matrix fails
       matrix:
         include:
-          - os: ubuntu
-            name: bionic
           - os: ubuntu
             name: focal
           - os: ubuntu
             name: jammy
           - os: ubuntu
             name: lunar
+          - os: ubuntu
+            name: mantic
           - os: archlinux
             name: latest
           - os: debian
@@ -77,7 +77,7 @@ jobs:
         with:
             submodules: 'recursive'
       - name: test install environment ${{matrix.os}}.${{matrix.name}}
-        timeout-minutes: 30
+        timeout-minutes: 45
         env:
           DISABLE_MAVNATIVE: True
           DEBIAN_FRONTEND: noninteractive