fix: 생일 설정 해놓지 않은 케이스 대응

mashup-domain/src/main/java/kr/mashup/branding/service/member/MemberProfileService.java

@@ -58,6 +58,7 @@ public List<MemberBirthdayDto> findByBirthDateBetween(MonthDay startDate, MonthD
 
     public boolean isBirthdayToday(long memberId) {
         return memberProfileRepository.findByMemberId(memberId)
+            .filter(memberProfile -> memberProfile.getBirthDate() != null)
             .filter(memberProfile -> MonthDay.now().equals(MonthDay.from(memberProfile.getBirthDate())))
             .isPresent();
     }