bug(mat-menu): VoiceOver user on mobile is able to navigate out of an opened Menu

### Description

On iOS, with VoiceOver turned on, after a user opens a menu and they start swiping through the menu items in order to move focus from one item to the next, when they reach the first or last menu item and swipe respectively backward or forward, VoiceOver focus is moved outside of the menu into the next element

### Reproduction

StackBlitz link: https://material.angular.dev/components/menu/overview#menu-overview
Steps to reproduce:
1. On an iOS device, turn VoiceOver on
2. Navigate to the menu example
3. Open the menu
4. Swipe forward until VoiceOver focus leaves the menu

### Expected Behavior

Focus is trapped in the menu

### Actual Behavior

VoiceOver focus moves outside of the menu

### Environment

- Angular: v21
- CDK/Material: v21
- Browser(s): Any
- Operating System (e.g. Windows, macOS, Ubuntu): iOS with VoiceOver turned on

まず、VoiceOverを有効にしたiOSデバイスで、リンクされたMaterial menu overviewの問題を再現し、次に最初と最後のメニュー項目におけるmat-menuのフォーカス処理を追跡します。完了条件は、前方向および後方向のスワイプによってVoiceOverのフォーカスが次の要素へ移動せず、開いたメニュー内に留まることです。

索引モデルが issue の本文から書いたものです。