feat: always delete the voice state (avoid memory leak)

Author: PandaGuerrier

lib/src/infrastructure/internals/packets/listeners/voice_leave_packet.dart

@@ -25,6 +25,8 @@ final class VoiceLeavePacket implements ListenablePacket {
         beforeRaw['channel_id'] != message.payload['channel_id']) {
       final before = await _marshaller.serializers.voice.serialize(beforeRaw);
       dispatch(event: Event.voiceLeave, params: [before]);
+
+      _marshaller.cache?.remove(cacheKey);
     }
   }
 }