Fix dag-processor logging

[jedcunningham]

Body

There are a couple logging related tasks that we need to tackle

• Get processor logs for individual files writing again - right now they don't land on disk anywhere
• Move the dag processor manager logs to stdout - we don't need the separate log file any longer

Committer

• I acknowledge that I am a maintainer/committer of the Apache Airflow project.

[jedcunningham]

This was done by #46355 and #45888.