feat: add clearing cache to switchUser

typings/index.d.ts

@@ -932,6 +932,7 @@ export class Client<Ready extends boolean = boolean> extends BaseClient {
   public customStatusAuto(client?: this): undefined;
   public authorizeURL(url: string, options?: object): Promise<boolean>;
   public sleep(milliseconds: number): Promise<void> | null;
+  public clearCache(cache: Collection<any, any>): void;
   public toJSON(): unknown;
 
   public on<K extends keyof ClientEvents>(event: K, listener: (...args: ClientEvents[K]) => Awaitable<void>): this;