fix: use "super.key"

lib/src/app.dart

@@ -15,7 +15,7 @@ import 'model/app_settings.dart';
 import 'pages/main_page.dart';
 
 class App extends StatefulWidget {
-  const App({Key? key}) : super(key: key);
+  const App({super.key});
 
   @override
   State<App> createState() => _AppState();

lib/src/pages/downloader.dart

@@ -15,11 +15,11 @@ import '../widgets/downloader/download_progress_bar.dart';
 
 class Downloader extends StatefulWidget {
   const Downloader({
-    Key? key,
     required this.operatingSystem,
     required this.version,
     this.option,
-  }) : super(key: key);
+    super.key,
+  });
 
   final OperatingSystem operatingSystem;
   final Version version;

lib/src/pages/downloader_page.dart

@@ -5,7 +5,7 @@ import '../widgets/home_page/downloader_menu.dart';
 import '../widgets/home_page/logo.dart';
 
 class DownloaderPage extends StatelessWidget {
-  const DownloaderPage({Key? key}) : super(key: key);
+  const DownloaderPage({super.key});
 
   @override
   Widget build(BuildContext context) {

lib/src/pages/main_page.dart

@@ -7,7 +7,7 @@ import '../widgets/home_page/main_menu.dart';
 import '../widgets/left_menu.dart';
 
 class MainPage extends StatefulWidget {
-  const MainPage({Key? key}) : super(key: key);
+  const MainPage({super.key});
 
   @override
   State<MainPage> createState() => _MainPageState();

lib/src/pages/manager.dart

@@ -19,7 +19,7 @@ import '../model/osicons.dart';
 /// Displays a list of available VMs, running state and connection info,
 /// with buttons to start and stop VMs.
 class Manager extends StatefulWidget {
-  const Manager({Key? key}) : super(key: key);
+  const Manager({super.key});
 
   @override
   State<Manager> createState() => _ManagerState();

lib/src/pages/operating_system_selection.dart

@@ -6,7 +6,7 @@ import '../model/operating_system.dart';
 import '../model/osicons.dart';
 
 class OperatingSystemSelection extends StatefulWidget {
-  const OperatingSystemSelection({Key? key}) : super(key: key);
+  const OperatingSystemSelection({super.key});
 
   @override
   State<OperatingSystemSelection> createState() =>

lib/src/pages/option_selection.dart

@@ -4,7 +4,7 @@ import 'package:gettext_i18n/gettext_i18n.dart';
 import '../model/version.dart';
 
 class OptionSelection extends StatefulWidget {
-  const OptionSelection(this.version, {Key? key}) : super(key: key);
+  const OptionSelection(this.version, {super.key});
 
   final Version version;
 

lib/src/pages/version_selection.dart

@@ -8,8 +8,7 @@ import '../model/version.dart';
 import 'option_selection.dart';
 
 class VersionSelection extends StatefulWidget {
-  const VersionSelection({Key? key, required this.operatingSystem})
-      : super(key: key);
+  const VersionSelection({required this.operatingSystem, super.key});
 
   final OperatingSystem operatingSystem;