remove gazebo build test. its installed from binary

Author: woensug-choi

.github/workflows/build.yml

@@ -27,13 +27,6 @@ jobs:
       - name: Run Test (ROS2 Jazzy)
         run: |
           source ~/ros2_jazzy/activate_ros && cd ~/ros2_jazzy && colcon test-result --all --verbose
-          if [ $? -ne 0 ]; then
-            exit 1
-          fi
-      
-      - name: Run Test (Gazebo Harmonic)
-        run: |
-          source ~/ros2_jazzy/activate_ros && cd ~/gz_harmonic && colcon test-result --all --verbose
           if [ $? -ne 0 ]; then
             exit 1
           fi