Enable more revive linter rules (#30608)

Noteable additions:

- `redefines-builtin-id` forbid variable names that shadow go builtins
- `empty-lines` remove unnecessary empty lines that `gofumpt` does not
remove for some reason
- `superfluous-else` eliminate more superfluous `else` branches

Rules are also sorted alphabetically and I cleaned up various parts of
`.golangci.yml`.

routers/private/hook_pre_receive.go

@@ -198,7 +198,6 @@ func preReceiveBranch(ctx *preReceiveContext, oldCommitID, newCommitID string, r
 				UserMsg: fmt.Sprintf("branch %s is protected from force push", branchName),
 			})
 			return
-
 		}
 	}