fix: accept list payload for trans_items in update_child_qty_rate

The whitelisted endpoint declared trans_items as str, so Frappe's typing
validation raised FrappeTypeError when the client sent the items as a
JSON list. ChildItemUpdater.update already handles both via
frappe.parse_json, so widen the wrapper's hint to str | list.

erpnext/accounts/services/child_item_update.py

@@ -314,7 +314,7 @@ class ChildItemUpdater:
 
 @frappe.whitelist()
 def update_child_qty_rate(
-	parent_doctype: str, trans_items: str, parent_doctype_name: str, child_docname: str = "items"
+	parent_doctype: str, trans_items: str | list, parent_doctype_name: str, child_docname: str = "items"
 ) -> None:
 	ChildItemUpdater(parent_doctype, parent_doctype_name, child_docname).update(trans_items)