bug([MatChipInput]): matChipInputAddOnBlur: true + selecting option by click inserts 2 chips

### Description

This is an intentional duplicate of https://github.com/angular/components/issues/19279, because it's been closed with a workaround that no longer works with the new Angular Material components (v15+).

The workaround was to set `matChipInputAddOnBlur` to `false` and handle the `(blur)` event on our own while ignoring the one that is related (`relatedTarget`) to `mat-option` element, however, now, clicking the `mat-option` will fire the `FocusEvent` with `relatedTarget: null`.

My updated (and working) workaround looks like this:
```
addOnBlur(event: FocusEvent) {
const target: HTMLElement = event.relatedTarget as HTMLElement;

if (!target) {
return;
}

this.addCustomChip(this.itemInput.nativeElement.value); // or manually create MatChipInputEvent etc...
}
```

However, the original issue is still there and it shouldn't require any workaround in the first place.

### Reproduction

https://stackblitz.com/edit/angular-rd38q1-b74xmz?file=src%2Fapp%2Fchips-autocomplete-example.ts,package.json,src%2Fapp%2Fchips-autocomplete-example.html,src%2Fmain.ts

### Expected Behavior

Only the selected option should become a chip

### Actual Behavior

The input text also becomes a chip

### Environment

- Angular: v15+
- CDK/Material: v15+
- Browser(s): Chrome
- Operating System (e.g. Windows, macOS, Ubuntu): Windows

リンクされている StackBlitz の再現コードから始め、特に src/app/chips-autocomplete-example.ts、src/app/chips-autocomplete-example.html、package.json を確認し、Chrome でクリックによる選択フローを再現します。mat-option を選択したときにそのオプションだけが chip として追加され、入力テキストも追加されなければ作業完了です。

索引モデルが issue の本文から書いたものです。