Tools: stop invoking setup.py directly

the command-line interface for setup.py is deprecated

See https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html

Tools/scripts/build_autotest.sh

@@ -71,13 +71,13 @@ pushd MAVProxy
 git fetch origin
 git reset --hard origin/master
 git show
-python setup.py build install --user
+python3 -m pip install --user .
 popd
 
 echo "Updating pymavlink"
 pushd APM/modules/mavlink/pymavlink
 git show
-python setup.py build install --user
+python3 -m pip install --user .
 popd
 
 githash=$(cd APM && git rev-parse HEAD)

Tools/scripts/build_ci.sh

@@ -40,7 +40,7 @@ function install_pymavlink() {
     if [ $pymavlink_installed -eq 0 ]; then
         echo "Installing pymavlink"
         git submodule update --init --recursive --depth 1
-        (cd modules/mavlink/pymavlink && python setup.py build install --user)
+        (cd modules/mavlink/pymavlink && python3 -m pip install --user .)
         pymavlink_installed=1
     fi
 }
@@ -51,7 +51,7 @@ function install_mavproxy() {
         pushd /tmp
           git clone https://github.com/ardupilot/MAVProxy --depth 1
           pushd MAVProxy
-            python setup.py build install --user --force
+            python3 -m pip install --user --force .
           popd
         popd
         mavproxy_installed=1