ignore new data on disposed socket

lib/src/support/websocket.dart

@@ -1,3 +1,4 @@
+import '../support/disposable.dart';
 import 'websocket/io.dart' if (dart.library.html) 'websocket/web.dart';
 
 class WebSocketException implements Exception {
@@ -29,9 +30,8 @@ class WebSocketEventHandlers {
   });
 }
 
-abstract class LiveKitWebSocket {
+abstract class LiveKitWebSocket extends Disposable {
   void send(List<int> data);
-  Future<void> dispose();
 
   static Future<LiveKitWebSocket> connect(
     Uri uri, [