docs: update core to use @publicApi tags (#26595)

PR Close #26595

packages/core/testing/src/test_bed.ts

@@ -635,6 +635,8 @@ export class TestBedViewEngine implements Injector, TestBed {
  *
  * Note: Use `TestBed` in tests. It will be set to either `TestBedViewEngine` or `TestBedRender3`
  * according to the compiler used.
+ *
+ * @publicApi
  */
 export const TestBed: TestBedStatic =
     ivyEnabled ? TestBedRender3 as any as TestBedStatic : TestBedViewEngine as any as TestBedStatic;
@@ -676,7 +678,7 @@ function _getTestBedViewEngine(): TestBedViewEngine {
  * eventually
  *   becomes `it('...', @Inject (object: AClass, async: AsyncTestCompleter) => { ... });`
  *
- *
+ * @publicApi
  */
 export function inject(tokens: any[], fn: Function): () => any {
   const testBed = getTestBed();