text: Title: Logging changes break the robot backgoundlogger
  Body: The changes in #5255 break the robot backgoundlogger. The import of the backgroundlogger failes:
  ```
  Traceback (most recent call last):
    File "/home/user/test/TestLib.py", line 2, in <module>
      from robotbackgroundlogger import BackgroundLogger
    File "/home/user/test/.venv/lib/python3.10/site-packages/robotbackgroundlogger.py", line 57, in <module>
      class BackgroundLogger(BaseLogger):
    File "/home/user/test/.venv/lib/python3.10/site-packages/robotbackgroundlogger.py", line 75, in BackgroundLogger
      LOGGING_THREADS = logger.librarylogger.LOGGING_THREADS
  AttributeError: module 'robot.output.librarylogger' has no attribute 'LOGGING_THREADS'
  ```