[iOS] Portuguese (Portugal) compound character entry creates extra character

### Steps to reproduce

1. Run the sample app in the iPad Air 13-inch emulator with iOS 17.5 with a Portuguese (Portugal) keyboard
2. Press `´` and then `a`

### Expected results

`Á` is inserted

### Actual results

`´á` is inserted

### Code sample

Code sample

```dart
import 'package:flutter/material.dart';

void main() {
runApp(
const MaterialApp(
home: Scaffold(
body: TextInputExample(),
),
),
);
}

class TextInputExample extends StatelessWidget {
const TextInputExample({super.key});

@override
Widget build(BuildContext context) {
return const Center(
child: Padding(
padding: EdgeInsets.all(8.0),
child: TextField(
autofocus: true,
),
),
);
}
}

```

### Screenshots or Video

Screenshots / Video demonstration

https://github.com/user-attachments/assets/9fe51c8e-298a-419e-aef2-09d098d57a3c

### Logs

Logs

No relevant logs.

### Flutter Doctor output

Doctor output

```console
$ flutter doctor -v
[✓] Flutter (Channel master, 3.25.0-1.0.pre.153, on macOS 15.0 24A335 darwin-arm64, locale en-BR)
• Flutter version 3.25.0-1.0.pre.153 on channel master at /Users/angelosilvestre/dev/flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 17f63272a0 (5 weeks ago), 2024-08-27 19:30:17 +0000
• Engine revision 7d751acc81
• Dart version 3.6.0 (build 3.6.0-175.0.dev)
• DevTools version 2.39.0-dev.15

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
• Android SDK at /Users/angelosilvestre/Library/Android/sdk
• Platform android-35, build-tools 34.0.0
• Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b829.9-10027231)
• All Android licenses accepted.

[!] Xcode - develop for iOS and macOS (Xcode 16.0)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Build 16A242d
! CocoaPods 1.12.1 out of date (1.13.0 is recommended).
CocoaPods is a package manager for iOS or macOS platform code.
Without CocoaPods, plugins will not work on iOS or macOS.
For more info, see https://flutter.dev/to/platform-plugins
To update CocoaPods, see https://guides.cocoapods.org/using/getting-started.html#updating-cocoapods

[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2022.3)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b829.9-10027231)

[✓] VS Code (version 1.93.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.98.0

[✓] Connected device (4 available)
• iPad Air 13-inch (M2) (mobile) • 9D3D13AF-EA1C-47A8-AADF-DEBF72D2C99E • ios •
com.apple.CoreSimulator.SimRuntime.iOS-17-5 (simulator)
• macOS (desktop) • macos • darwin-arm64 • macOS 15.0 24A335 darwin-arm64
• Mac Designed for iPad (desktop) • mac-designed-for-ipad • darwin • macOS 15.0 24A335 darwin-arm64
• Chrome (web) • chrome • web-javascript • Google Chrome 129.0.6668.90

[✓] Network resources
• All expected network resources are available.

! Doctor found issues in 1 category.
```