apply sorting for make multiple variant attributes (#14060)

diff --git a/erpnext/stock/doctype/item/item.js b/erpnext/stock/doctype/item/item.js
index 86594a2..a262bf6 100644
--- a/erpnext/stock/doctype/item/item.js
+++ b/erpnext/stock/doctype/item/item.js
@@ -458,7 +458,8 @@
 						fields: ["attribute_value"],
 						limit_start: 0,
 						limit_page_length: 500,
-						parent: "Item"
+						parent: "Item",
+						order_by: "idx"
 					}
 				}).then((r) => {
 					if(r.message) {