* Disable federation by default (#20045)
- Backport #20045
- A Gitea instance should choose whetever they want to federate(as once it has more features also brings extra costs/moderation/unexpected behavior) with other AP/ForgeFed software.
* Fix tests
- Don't use hacky solution to limit to the correct RepoID's, instead use
current code to handle these limits. The existing code is more correct
than the hacky solution.
- Resolves #19636
- Add test-case
