bug: Unintended Voiceover Output in Default ion-select Popup

### Prerequisites

- [X] I have read the [Contributing Guidelines](https://github.com/ionic-team/ionic-framework/blob/main/docs/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

v8.x

### Current Behavior

Toggling between two selected options in the default ion-select popup (md or ios mode) results in unintended voiceover output (iOs 16 and 17 physical devices)

Steps to Recreate
1). With voiceover activated on a physical iOs device, click to open the Test ion-select.
2). Select (double tap) any option, like Yellow.
3). Select another option, like Red. Notice that voiceover outputs "Yellow, Red", instead of just "Red".
4). Select "Yellow" again. Voiceover outputs "Yellow, Red", instead of just "Yellow".

### Expected Behavior

Voiceover should output only the selected ion-option text.

### Steps to Reproduce

Steps to Recreate
1). With voiceover on, click to open the Test ion-select.
2). Select any option, like Yellow.
3). Select another option, like Red. Notice that voiceover outputs "Yellow, Red", instead of just "Red".
4). Select "Yellow" again. Voiceover outputs "Yellow, Red", instead of just "Yellow".

### Code Reproduction URL

https://github.com/jwburnside/ion-select-test/tree/main

### Ionic Info

Ionic:

Ionic CLI : 7.2.0 (/Users/j/.nvm/versions/node/v18.20.2/lib/node_modules/@ionic/cli)
Ionic Framework : @ionic/angular 8.3.1
@angular-devkit/build-angular : 18.2.6
@angular-devkit/schematics : 18.2.6
@angular/cli : 18.2.6
@ionic/angular-toolkit : 11.0.1

Capacitor:

Capacitor CLI : 6.1.2
@capacitor/android : not installed
@capacitor/core : 6.1.2
@capacitor/ios : 6.1.2

Utility:

cordova-res : not installed globally
native-run : 2.0.1

System:

NodeJS : v18.20.2 (/Users/j/.nvm/versions/node/v18.20.2/bin/node)
npm : 10.5.0
OS : macOS Unknown

### Additional Information
Tested in iOs 16x and iOs 17x physical devices. I have not tested on Android. Reproduction of the bug is attached below.

https://github.com/user-attachments/assets/d04c1aa7-6248-419e-98e3-00bfa7db6fbf

Start with the linked reproduction and reproduce the default ion-select popup behavior on a physical iOS device with VoiceOver enabled. Compare announcements when switching between options, and consider the work complete when only the currently selected ion-option text is announced.

索引モデルが issue の本文から書いたものです。