[backport] v1.16 fix gazebo install on ROS integration tests

[mrpollo]

Fixes the gazebo install for the ROS integration tests

[dakejahl]

CI failure is real

Starting >>> px4_ros2_cpp
--- stderr: px4_ros2_cpp
In file included from /opt/px4_ws/src/px4-ros2-interface-lib/px4_ros2_cpp/src/control/setpoint_types/fixedwing_lateral_longitudinal.cpp:6:
/opt/px4_ws/src/px4-ros2-interface-lib/px4_ros2_cpp/include/px4_ros2/control/setpoint_types/fixedwing_lateral_longitudinal.hpp:8:10: fatal error: px4_msgs/msg/fixed_wing_lateral_setpoint.hpp: No such file or directory
    8 | #include <px4_msgs/msg/fixed_wing_lateral_setpoint.hpp>
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

[mrpollo]

I guess the gazebo failure was hiding this issue, we gotta get this fixed

[mrpollo]

@bkueng any idea where this is coming from?

[bkueng]

Those messages got added after the 1.16 release. There's a matching release branch that we need to use for the integration tests. I added a change for that in 476a8b8. Let's see if it passes now.

[sansha]

Test passes now! 😍