Remove Logger.mongo_process_id

[BigRoy]

Changelog Description

Remove Logger.mongo_process_id

Additional info

Was once used a long time ago in ftrack services back in OpenPype era?

Testing notes:

1. Logger should work
2. Addons should still work (esp. ftrack)

[iLLiCiTiT]

Was once used a long time ago in ftrack services back in OpenPype era?

Yes, Logger did store logs to mongo, and because ftrack does create subprocess this helped to store it under same process (and see in logs viewer the same in console).