feat: 전화번호, 코드 기반 인증 코드 조회 로직 정의(#28)

be/src/main/java/yeonba/be/login/repository/VerificationCodeRepository.java

@@ -0,0 +1,10 @@
+package yeonba.be.login.repository;
+
+import java.util.Optional;
+import org.springframework.data.jpa.repository.JpaRepository;
+import yeonba.be.login.entity.VerificationCode;
+
+public interface VerificationCodeRepository extends JpaRepository<VerificationCode, Long> {
+
+	Optional<VerificationCode> findByPhoneNumberAndCode(String phoneNumber, String code);
+}