Revert "apply sorting for make multiple variant attributes (#14060)" (#14065)

This reverts commit 257e18b6400dc0363e158134f42b8bc28136dc08.
diff --git a/erpnext/stock/doctype/item/item.js b/erpnext/stock/doctype/item/item.js
index a262bf6..86594a2 100644
--- a/erpnext/stock/doctype/item/item.js
+++ b/erpnext/stock/doctype/item/item.js
@@ -458,8 +458,7 @@
 						fields: ["attribute_value"],
 						limit_start: 0,
 						limit_page_length: 500,
-						parent: "Item",
-						order_by: "idx"
+						parent: "Item"
 					}
 				}).then((r) => {
 					if(r.message) {