.github: install microxrceddsgen from source

... until image is udpated

Author: peterbarker

.github/workflows/test_dds.yml

@@ -169,6 +169,14 @@ jobs:
       - name: setup ccache
         run: |
           . .github/workflows/ccache.env
+      # install install Micro-XRCE-DDS-Gen from source until image is updated
+      - name: install Micro-XRCE-DDS-Gen from source
+        run: |
+          cd /tmp
+          git clone --recurse-submodules https://github.com/ardupilot/Micro-XRCE-DDS-Gen.git
+          cd Micro-XRCE-DDS-Gen
+          time ./gradlew assemble
+          echo "export PATH=\$PATH:$PWD/scripts" >> ~/.bashrc
       - name: test ${{matrix.config}}
         env:
           CI_BUILD_TARGET: dds-${{matrix.config}}