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/common/http/testing/src/module.ts

@@ -18,7 +18,7 @@ import {HttpClientTestingBackend} from './backend';
  *
  * Inject `HttpTestingController` to expect and flush requests in your tests.
  *
- * @stable
+ *
  */
 @NgModule({
   imports: [