ci: fix missing sourcing of the ROS setup script (#521)

Signed-off-by: Esteve Fernandez <esteve@apache.org>

Author: esteve

.github/workflows/generate-bindings.yml

@@ -65,6 +65,7 @@ jobs:
 
     - name: Generate bindings
       run: |
+        . /opt/ros/${{ matrix.ros_distribution }}/setup.sh
         cd rclrs/src
         ../generate_bindings.py rcl_wrapper.h ${{ matrix.ros_distribution }} .