Backport #25537
More fix for #24981
* #24981Close#22361, #25552
* #22361
* #25552
There were many patches for Gitea's sub-commands to satisfy the facts:
* Some sub-commands shouldn't output any log, otherwise the git protocol
would be broken
* Sometimes the users want to see "verbose" or "quiet" outputs
That's a longstanding problem, and very fragile. This PR is only a quick
patch for the problem.
In the future, the sub-command system should be refactored to a clear
solution.
----
Other changes:
* Use `ReplaceAllWriters` to replace
`RemoveAllWriters().AddWriters(writer)`, then it's an atomic operation.
* Remove unnecessary `syncLevelInternal` calls, because
`AddWriters/addWritersInternal` already calls it.
0eb4ab4246