UTKProperty 버그 수정. Validation 추가 해야 함

Assets/Scripts/UVC/UIToolkit/Input/UTKIntegerField.cs

@@ -151,7 +151,9 @@ namespace UVC.UIToolkit
             }
         }
 
-        [UxmlAttribute("is-readonly")]
+        /// <summary>
+        /// 읽기 전용
+        /// </summary>
         public new bool isReadOnly
         {
             get => base.isReadOnly;