neon, app: don't require widget WidgetsBinding

packages/app/integration_test/screenshot_test.dart

@@ -93,9 +93,9 @@ Future runTestApp(
   final Account? account,
 }) async {
   await runNeon(
-    binding: binding,
     getAppImplementations: getAppImplementations,
     branding: getNeonBranding(),
+    bindingOverride: binding,
     sharedPreferencesOverride: MemorySharedPreferences(),
     account: account,
     firstLaunchDisabled: true,

packages/app/lib/main.dart

@@ -1,11 +1,9 @@
 import 'package:app/apps.dart';
 import 'package:app/branding.dart';
-import 'package:flutter/material.dart';
 import 'package:neon/neon.dart';
 
 Future main() async {
   await runNeon(
-    binding: WidgetsFlutterBinding.ensureInitialized(),
     getAppImplementations: getAppImplementations,
     branding: getNeonBranding(),
   );

packages/neon/neon/lib/neon.dart

@@ -102,15 +102,16 @@ part 'src/widgets/text_settings_tile.dart';
 part 'src/widgets/user_avatar.dart';
 
 Future runNeon({
-  required final WidgetsBinding binding,
   required final Iterable<AppImplementation> Function(SharedPreferences, RequestManager, NeonPlatform)
       getAppImplementations,
   required final Branding branding,
+  final WidgetsBinding? bindingOverride,
   final SharedPreferences? sharedPreferencesOverride,
   final Account? account,
   final bool firstLaunchDisabled = false,
   final bool nextPushDisabled = false,
 }) async {
+  final binding = bindingOverride ?? WidgetsFlutterBinding.ensureInitialized();
   FlutterNativeSplash.preserve(widgetsBinding: binding);
 
   final sharedPreferences = sharedPreferencesOverride ?? await SharedPreferences.getInstance();