When setting both, onTextChanged and Controller the onTextChanged callback is called twice

[carlos-enzo]

Describe the bug
When we set a callback for onTextChanged and a controller the callback is called twice.

To Reproduce
example code:

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

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  TextEditingController _controller = TextEditingController();

  @override
  void initState() {
    super.initState();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Connectivity example app'),
      ),
      body: Center(
        child: PinCodeTextField(
          onTextChanged: onTextChanged, //widget.onTextChanged,
          controller: _controller,
          pinBoxColor: Colors.transparent,
          pinBoxBorderWidth: 1.0,
          pinBoxOuterPadding: const EdgeInsets.all(2.5),
          pinBoxWidth: 40,
          pinBoxHeight: 40,
          pinBoxRadius: 2.0,
          focusNode: FocusNode(),
        ),
      ),
    );
  }

  void onTextChanged(String value) {
    print('value: $value');
  }
}

Expected behavior
We can set the controller and the callback and when the text changes, the callback is only called once.

** flutter doctor **
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[✓] Flutter (Channel stable, 2.10.3, on macOS 12.1 21C52 darwin-x64, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 32.0.0)
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