Fix issue

Author: martijn00

example/lib/home_page.dart

@@ -2,7 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:form_builder_validators/form_builder_validators.dart';
 
 class HomePage extends StatefulWidget {
-  const HomePage({Key? key}) : super(key: key);
+  const HomePage({super.key});
 
   @override
   HomePageState createState() => HomePageState();

example/lib/main.dart

@@ -10,7 +10,7 @@ void main() {
 }
 
 class MyApp extends StatelessWidget {
-  const MyApp({Key? key}) : super(key: key);
+  const MyApp({super.key});
 
   @override
   Widget build(BuildContext context) {