fix: sonar qube 이슈 수정

Author: leebs0521

src/test/java/com/somemore/interestcenter/service/CancelInterestCenterServiceTest.java

@@ -72,7 +72,6 @@ void cancelInterestCenter_AlreadyDeleted_ShouldThrowException() {
         cancelInterestCenterUseCase.cancelInterestCenter(volunteerId, centerId);
 
         //when, then
-        long interestCenterId = responseDto.id();
         assertThrows(BadRequestException.class,
                 () -> cancelInterestCenterUseCase.cancelInterestCenter(volunteerId, centerId),
                 CANNOT_CANCEL_DELETED_INTEREST_CENTER.getMessage()