Fix sub-command log level (#25537)

More fix for #24981

* #24981


Close #22361

* #22361

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.

Co-authored-by: Giteabot <teabot@gitea.io>

cmd/keys.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"strings"
 
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/private"
 
 	"github.com/urfave/cli"
@@ -17,6 +18,7 @@ import (
 var CmdKeys = cli.Command{
 	Name:   "keys",
 	Usage:  "This command queries the Gitea database to get the authorized command for a given ssh key fingerprint",
+	Before: PrepareConsoleLoggerLevel(log.FATAL),
 	Action: runKeys,
 	Flags: []cli.Flag{
 		cli.StringFlag{