chore(repo): updated minimum supported SDK version to Flutter 3.10/Dart 3.0

Signed-off-by: xsahil03x <[email protected]>
Signed-off-by: Sahil Kumar <[email protected]>

packages/stream_chat/lib/src/ws/timer_helper.dart

@@ -2,7 +2,7 @@ import 'dart:async';
 import 'package:uuid/uuid.dart';
 
 ///
-class TimerHelper {
+mixin class TimerHelper {
   final _uuid = const Uuid();
   late final _timers = <String, Timer>{};