feat: setter -> builder() 패턴으로 변경

Author: dohy-eon

src/main/java/dmu/dasom/api/domain/news/service/NewsService.java

@@ -42,4 +42,5 @@ public NewsResponseDto createNews(NewsRequestDto requestDto) {
         NewsEntity savedNews = newsRepository.save(news);
         return savedNews.toResponseDto();
     }
+
 }