perf(backend): Improve performance of FetchInstanceMetadata (#11128)

* Perf: Avoid retries to acquire lock in fetchInstanceMetadata

* Fix

* Add Changelog

* Fix typo

* Fix lint

* 記法をMisskey式にする

* ????

* refactor
https://github.com/misskey-dev/misskey/pull/11128#pullrequestreview-1518059366

* refactor

* getいらない？

* fix

* fix

* Update CHANGELOG.md

* clean up

---------

Co-authored-by: tamaina <tamaina@hotmail.co.jp>

packages/backend/src/core/AppLockService.ts

@@ -32,11 +32,6 @@ export class AppLockService {
 		return this.lock(`ap-object:${uri}`, timeout);
 	}
 
-	@bindThis
-	public getFetchInstanceMetadataLock(host: string, timeout = 30 * 1000): Promise<() => void> {
-		return this.lock(`instance:${host}`, timeout);
-	}
-
 	@bindThis
 	public getChartInsertLock(lockKey: string, timeout = 30 * 1000): Promise<() => void> {
 		return this.lock(`chart-insert:${lockKey}`, timeout);