style: 중복 메서드 제거

src/main/java/com/moabam/api/application/coupon/CouponService.java

@@ -60,7 +60,7 @@ public void delete(AuthMember admin, Long couponId) {
 
 	@Transactional
 	public void use(Long memberId, Long couponWalletId) {
-		Coupon coupon = getByWallet(memberId, couponWalletId);
+		Coupon coupon = getByWalletIdAndMemberId(couponWalletId, memberId);
 		couponRepository.delete(coupon);
 	}
 
@@ -71,12 +71,6 @@ public CouponResponse getById(Long couponId) {
 		return CouponMapper.toResponse(coupon);
 	}
 
-	public Coupon getByWallet(Long memberId, Long couponWalletId) {
-		return couponWalletRepository.findByIdAndMemberId(couponWalletId, memberId)
-			.orElseThrow(() -> new NotFoundException(ErrorMessage.NOT_FOUND_COUPON_WALLET))
-			.getCoupon();
-	}
-
 	public List<CouponResponse> getAllByStatus(CouponStatusRequest request) {
 		LocalDate now = clockHolder.date();
 		List<Coupon> coupons = couponSearchRepository.findAllByStatus(now, request);