[Docs] Links to ur_dashboard_msgs documentation seem broken

[urfeex]

Since recently, our check_links workflow reports broken links for ur_dashboard_msgs documentation pages:

Failed files:
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/AddToLog.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/GetLoadedProgram.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/GetRobotMode.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/GetSafetyMode.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/Load.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/Load.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/Popup.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/IsProgramRunning.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/IsProgramSaved.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/GetProgramState.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/GetLoadedProgram.html from file ur_robot_driver/doc/dashboard_client.rst
http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/interfaces/srv/RawRequest.html from file ur_robot_driver/doc/dashboard_client.rst
https://index.ros.org/p/ur_robot_driver/github-UniversalRobots-Universal_Robots_ROS2_Driver/ from file ur_controllers/doc/index.rst

It seems. that the correct link would be e.g. http://docs.ros.org/en/rolling/p/ur_dashboard_msgs/srv/AddToLog.html but that's not consistent with other ROS packages. I don't know at this point whether this has changed recently or if that's just a fluke from the buildfarm.