[EA3-209] refactor: 모집글 저장시 모집 기간 수정

Author: Tokwasp

src/main/java/grep/neogulcoder/domain/recruitment/post/service/RecruitmentPostSaveService.java

@@ -36,7 +36,7 @@ public long create(RecruitmentPostCreateServiceRequest request, long userId) {
             throw new BusinessException(NOT_STUDY_LEADER);
         }
 
-        if(isStudyAlreadyEndedDateTime(studyMember.getStudy(), request.getExpiredDate())){
+        if(studyMember.getStudy().hasEndDateBefore(request.getExpiredDate())){
             throw new BusinessException(END_DATE_ERROR);
         }
 
@@ -57,10 +57,6 @@ public JoinedStudyLoadInfo getJoinedStudyLoadInfo(long studyId, long userId) {
         return JoinedStudyLoadInfo.of(study, remainSlots);
     }
 
-    private boolean isStudyAlreadyEndedDateTime(Study study, LocalDateTime expiredDateTime) {
-        return study.hasEndDateBefore(expiredDateTime);
-    }
-
     private boolean isNotParticipated(StudyMember studyMember) {
         return studyMember == null;
     }