Cache also .venv for mujoco_ros2_control (#812)

Author: christophfroehlich

.github/workflows/reusable-industrial-ci-with-cache.yml

@@ -146,7 +146,9 @@ jobs:
         # save if build step succeeded, but only on default branch to save disk space
         if: ${{ always() && github.ref == format('refs/heads/{0}', github.event.repository.default_branch) && steps.ici.outputs.build_target_workspace == '0' }}
         with:
-          path: ${{ env.CCACHE_DIR }}
+          path: |
+            ${{ env.CCACHE_DIR }}
+            /root/.ros/ros2_control/.venv
           key: ccache-${{ env.CACHE_PREFIX }}-${{ github.sha }}-${{ github.run_id }}
 
       - name: Download issue template for target failure  # Has to be a local file