fix: 불필요한 로직 삭제

Author: yeonjiyeon

apps/commerce-api/src/main/java/com/loopers/domain/user/User.java

@@ -18,7 +18,7 @@ public class User {
   private static final String EMAIL_PATTERN = "^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,6}$";
   private static final String BIRTHDATE_PATTERN = "^\\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12]\\d|3[01])$";
 
-  @Id()
+  @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private Long id;
   String userId;

apps/commerce-api/src/main/java/com/loopers/domain/user/UserService.java

@@ -16,7 +16,6 @@ public UserResponse signUp(UserCreationCommand command) {
       throw new IllegalArgumentException("이미 가입된 ID입니다.");
     });
 
-    userRepository.findByUserId(command.userId());
     User user = userRepository.save(command.toUser());
     return UserResponse.from(user);
   }