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/test_bed.ts

@@ -55,7 +55,7 @@ export type TestModuleMetadata = {
  *
  * TestBed is the primary api for writing unit tests for Angular applications and libraries.
  *
- * @stable
+ *
  */
 export class TestBed implements Injector {
   /**
@@ -606,7 +606,7 @@ export function getTestBed() {
  * eventually
  *   becomes `it('...', @Inject (object: AClass, async: AsyncTestCompleter) => { ... });`
  *
- * @stable
+ *
  */
 export function inject(tokens: any[], fn: Function): () => any {
   const testBed = getTestBed();