🗑️ remove: 타이머 객체 정리 삭제

Author: LimKangHyun

backend/src/main/java/io/f1/backend/domain/game/app/TimerService.java

@@ -40,7 +40,7 @@ public boolean validateCurrentRound(Room room) {
             return true;
         }
         cancelTimer(room);
-        room.getScheduler().shutdown();
+//        room.getScheduler().shutdown();
         return false;
     }