Launching a paused simulation makes spawners from the same launchfile fail

[christophfroehlich]

After the refactoring done by ros-controls/ros2_control#1638, the switch_controller service has a working timeout for each controller. This time is hardcoded within the spawner.py to 5s.

If the simulation is started paused, like with

    gazebo = IncludeLaunchDescription(
                PythonLaunchDescriptionSource([os.path.join(
                    get_package_share_directory('gazebo_ros'), 'launch'), '/gazebo.launch.py']),
                launch_arguments={
                    'pause': 'true'}.items()
             )

then the CM services are started but the update method is not called yet. This leads to running into the timeout

[gzserver-5] [ERROR] [1727713930.188912404] [controller_manager]: Switch controller timed out after 5.000000 seconds!
[spawner-18] [ERROR] [1727713930.190697406] [spawner_joint_state_broadcaster]: Failed to activate controller

The same happens if a running simulation is paused and a service call to the CM is done.