Add missing source command

Signed-off-by: Ryan Friedman <[email protected]>

.github/workflows/build_test.yml

@@ -30,6 +30,7 @@ jobs:
     - name: Colcon Build (Release)
       working-directory: 
       run: |
+        source /opt/ros/${{matrix.config.rosdistro}}/setup.bash
         colcon build --cmake-args -DCMAKE_BUILD_TYPE=Release --packages-up-to grid_map_geo
       shell: bash
     # - name: unit_tests