bug: firefox, focus event does not fire when delegating focus

### Prerequisites

- [X] I have read the [Contributing Guidelines](https://github.com/ionic-team/ionic-framework/blob/main/.github/CONTRIBUTING.md#creating-an-issue).
- [X] I agree to follow the [Code of Conduct](https://ionicframework.com/code-of-conduct).
- [X] I have searched for [existing issues](https://github.com/ionic-team/ionic-framework/issues) that already report this problem, without success.

### Ionic Framework Version

- [ ] v4.x
- [ ] v5.x
- [X] v6.x

### Current Behavior

When the user clicks on an `` the focus is delegated to the first focusable element, in my case an ``. In this matter I was expecting the `` to fire with it's respective `(ionFocus)` event, which is unfortunatley not the case. I also tried to add a native `(focus)` event listener, which also does not seem to get triggered.

### Expected Behavior

When the user clicks on an `` the focus should get delegated to the ``, which should then fire an `(ionFocus)` event.

### Steps to Reproduce

See Stackblitz minimal reproduction code below.

### Code Reproduction URL

https://stackblitz.com/edit/ionic6-angular13-gqcrhl?file=src/app/app.component.html

### Ionic Info

```
Ionic:

Ionic CLI : 6.16.3 (/usr/local/lib/node_modules/@ionic/cli)
Ionic Framework : @ionic/angular 6.0.14
@angular-devkit/build-angular : 13.3.1
@angular-devkit/schematics : 13.3.1
@angular/cli : 13.3.1
@ionic/angular-toolkit : 6.1.0

Capacitor:

Capacitor CLI : 3.4.3
@capacitor/android : 3.4.3
@capacitor/core : 3.4.3
@capacitor/ios : 3.4.3

Utility:

cordova-res : not installed globally
native-run : 1.5.0

System:

NodeJS : v14.17.6 (/Users/felixgeissler/.nvm/versions/node/v14.17.6/bin/node)
npm : 6.14.15
OS : macOS Monterey
```

### Additional Information

In my case, this is a real show stopper since I'm trying to use my `` as a focus trigger to open an `` in a popover and I don't want the user to enter something in the input manually. With this approach I need a hook to open the popover once the focus is delegated to the ``.

Start with the linked StackBlitz reproduction and inspect how ion-item delegates focus to ion-input in Firefox. Verify whether the delegated element emits the native focus and ionFocus events, then confirm the fix against the reproduction and expected focus behavior.

索引モデルが issue の本文から書いたものです。