refactor: 트랜잭션 조회 명시 추가

backend/src/main/java/reviewme/review/service/ReviewService.java

@@ -72,7 +72,7 @@ private void saveReviewKeywords(List<Long> selectedKeywordIds, long savedReviewI
         reviewKeywordRepository.saveAll(reviewKeywords);
     }
 
-    @Transactional
+    @Transactional(readOnly = true)
     public ReviewSetupResponse findReviewCreationSetup(String reviewRequestCode) {
         ReviewGroup reviewGroup = reviewGroupRepository.findByReviewRequestCode(reviewRequestCode)
                 .orElseThrow(InvalidReviewRequestCodeException::new);