chore: Java 스타일 수정

Author: github-actions

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

@@ -15,7 +15,6 @@
 import io.f1.backend.domain.game.dto.MessageType;
 import io.f1.backend.domain.game.dto.RoomEventType;
 import io.f1.backend.domain.game.dto.request.GameSettingChanger;
-import io.f1.backend.domain.game.dto.response.PlayerListResponse;
 import io.f1.backend.domain.game.event.GameCorrectAnswerEvent;
 import io.f1.backend.domain.game.event.GameTimeoutEvent;
 import io.f1.backend.domain.game.event.RoomUpdatedEvent;