Remove pack-objects limiting by user_id and repository

For #4769 (closed)

This merge request removes pack-objects limiting by user_id and repository because:

• Accounting based on user identity is not effective due to the majority of requests needing to be more anonymous.
• One problem with restricting pack-objects commands to specific repositories is that repository sizes can vary greatly on a node, and the traffic directed to each repository can also differ significantly. This makes using repositories as the basis for limiting the commands ineffective. If the limit is set too low, it can unfairly affect larger repositories, while setting it too high can reduce its protective effect.

Using RemoteIP is a more effective strategy: Add pack-objects concurrency limiter based on R... (!5583 - merged). We don't enable neither of them on production. It's safe to remove.