docs: remove all deprecated @stable jsdoc tags (#23210)

These are no longer needed as stable docs are computed as those that
do not have `@experimental` or `@deprecated` tags.

PR Close #23210

packages/core/testing/src/async.ts

@@ -23,7 +23,7 @@ import {asyncFallback} from './async_fallback';
  * });
  * ```
  *
- * @stable
+ *
  */
 export function async(fn: Function): (done: any) => any {
   const _Zone: any = typeof Zone !== 'undefined' ? Zone : null;