[General]: Field deletion in the dynamic form example is not working properly.

Is there an existing issue for this?

[X] I have searched the existing issues

Package/Plugin version

9.2.1

Platforms

[X] Android
[ ] iOS
[ ] Linux
[ ] MacOS
[X] Web
[X] Windows

Flutter doctor

```bash Doctor summary (to see all details, run flutter doctor -v): [√] Flutter (Channel stable, 3.22.0, on Microsoft Windows [versão 10.0.22631.3593], locale pt-BR) [√] Windows Version (Installed version of Windows is version 10 or higher) [√] Android toolchain - develop for Android devices (Android SDK version 35.0.0-rc4) [√] Chrome - develop for the web [√] Visual Studio - develop Windows apps (Ferramentas de Build do Visual Studio 2022 17.8.0) [√] Android Studio (version 2023.1) [√] Connected device (3 available) [√] Network resources • No issues found! ```

Minimal code example

Code sample

```dart import 'package:flutter/material.dart'; import 'package:flutter_form_builder/flutter_form_builder.dart'; import 'package:form_builder_validators/form_builder_validators.dart'; void main() => runApp(const MaterialApp( home: Scaffold( body: Padding( padding: EdgeInsets.all(8.0), child: DynamicFields(), ), ), )); class DynamicFields extends StatefulWidget { const DynamicFields({Key? key}) : super(key: key); @override State createState() => _DynamicFieldsState(); } class _DynamicFieldsState extends State { final _formKey = GlobalKey(); final List fields = []; String savedValue = ''; @override void initState() { savedValue = _formKey.currentState?.value.toString() ?? ''; super.initState(); } @override Widget build(BuildContext context) { return FormBuilder( key: _formKey, // IMPORTANT to remove all references from dynamic field when delete clearValueOnUnregister: true, child: Column( children: [ const SizedBox(height: 20), FormBuilderTextField( name: 'name', validator: FormBuilderValidators.required(), decoration: const InputDecoration( label: Text('Started field'), ), ), ...fields, const SizedBox(height: 10), Row( children: [ Expanded( child: MaterialButton( color: Theme.of(context).colorScheme.secondary, child: const Text( "Submit", style: TextStyle(color: Colors.white), ), onPressed: () { _formKey.currentState!.saveAndValidate(); setState(() { savedValue = _formKey.currentState?.value.toString() ?? ''; }); }, ), ), const SizedBox(width: 20), Expanded( child: MaterialButton( color: Theme.of(context).colorScheme.secondary, child: const Text( "Add field", style: TextStyle(color: Colors.white), ), onPressed: () { setState(() { fields.add(NewTextField( name: 'name_${fields.length}', onDelete: () { setState(() { fields.removeAt(fields.length - 1); }); }, )); }); }, ), ), ], ), const Divider(height: 40), Text('Saved value: $savedValue'), ], ), ); } } class NewTextField extends StatelessWidget { const NewTextField({ super.key, required this.name, this.onDelete, }); final String name; final VoidCallback? onDelete; @override Widget build(BuildContext context) { return Padding( padding: const EdgeInsets.only(bottom: 8), child: Row( children: [ Expanded( child: FormBuilderTextField( name: name, validator: FormBuilderValidators.minLength(4), decoration: const InputDecoration( label: Text('New field'), ), ), ), IconButton( icon: const Icon(Icons.delete_forever), onPressed: onDelete, ), ], ), ); } } ```

Current Behavior

Each added text field has an icon ¹ which indicates that, on click, the respective added text field will be deleted.

But, only the last one is deleted ².

Expected Behavior

Clicking on a delete icon ¹ should remove only the corresponding form text field, even if it was not the last one added.

Steps To Reproduce

Run the script provided
Fill the title field
Add a field and fill it with the value Content0
Add a field and fill it with the value Content1
Add a field and fill it with the value Content2
Press the button Submit The result is:
Click on the delete button related to "Content1" field:
Press the button Submit and notice that the field with Content2 was deleted, not the one with Content1

Aditional information

No response

flutter-form-builder-ecosystem / flutter_form_builder