This appears to be left over from copying the setup.py from launch_testing when this package was originally created. The glob doesn't match anything so it's not an error, but it can sometimes result in installing an empty directory.
* [#791 Drop unused data_files entry for example_processes (backport #680)](https://github.com/ros2/launch/pull/791) has been created for branch `humble`
This appears to be left over from copying the setup.py from launch_testing when this package was originally created. The glob doesn't match anything so it's not an error, but it can sometimes result in installing an empty directory.