Some symbols not picked up by documentation infrastructure

### Is this a regression?

- [ ] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

_No response_

### Description

`MatSelect` waits for a CSS `animationend` event to close, which never fires in the JSDOM test environment.

- Zone change detection works
- Zoneless CD with `provideNoopAnimations()` works

Since (a) the dependency on the `animations` package was removed in Sept 2025, and (b) within the `animations` package, `provideNoopAnimations()` is scheduled to go away in `v23`, I am wondering what the recommended path will be.

Our current workaround is to inject `ANIMATION_MODULE_TYPE` in our tests. e.g.)

```ts
await TestBed.configureTestingModule({
imports: [...],
providers: [
provideZonelessChangeDetection(),
{ provide: ANIMATION_MODULE_TYPE, useValue: 'NoopAnimations' },
],
}).compileComponents();
```

### Reproduction

StackBlitz link:
Steps to reproduce:
1.
2.

### Expected Behavior

A standardized way to test without `provideNoopAnimations()`.

### Actual Behavior

Tests that depend on waiting for the mat-select overlay to close fail.

### Environment

- Angular:
- CDK/Material:
- Browser(s):
- Operating System (e.g. Windows, macOS, Ubuntu):

まず、JSDOM テスト環境で MatSelect オーバーレイを閉じる際の失敗を再現し、CSS アニメーションイベント animationend を待機している箇所を追跡します。その経路を、ANIMATION_MODULE_TYPE と provideNoopAnimations() を使用した、提供されている TestBed の回避策と比較します。標準化されたテスト手順を特定して文書化できれば完了です。

索引モデルが issue の本文から書いたものです。