Fix sound rendering for web

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

lib/game_select_screen.dart

@@ -59,7 +59,7 @@ class GameSelectScreen extends StatelessWidget {
     );
   }
 
-  Future<List<WolfensteinData>> loadData([String? directory]) async {
+  Future<List<WolfensteinData>> loadData({String? directory}) async {
     final List<WolfensteinData> loadedGames = [];
 
     // 1. Always attempt to load bundled assets first (works on ALL platforms)