fix: birthDate 필드의 컬럼 이름을 'birth_date'로 변경

Author: rnqhstmd

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

@@ -28,6 +28,7 @@ public class User extends BaseEntity {
     private Email email;
 
     @Embedded
+    @AttributeOverride(name = "value", column = @Column(name = "birth_date", nullable = false, length = 10))
     private BirthDate birthDate;
 
     @Enumerated(EnumType.STRING)