fix: use item_code instead of parent field in bom_stock_calculated report (#29684)

diff --git a/erpnext/manufacturing/report/bom_stock_calculated/bom_stock_calculated.py b/erpnext/manufacturing/report/bom_stock_calculated/bom_stock_calculated.py
index 090a3e7..2693352 100644
--- a/erpnext/manufacturing/report/bom_stock_calculated/bom_stock_calculated.py
+++ b/erpnext/manufacturing/report/bom_stock_calculated/bom_stock_calculated.py
@@ -89,10 +89,10 @@
 			GROUP BY bom_item.item_code""".format(qty_field=qty_field, table=table, conditions=conditions, bom=bom), as_dict=1)
 
 def get_manufacturer_records():
-	details = frappe.get_all('Item Manufacturer', fields = ["manufacturer", "manufacturer_part_no", "parent"])
+	details = frappe.get_all('Item Manufacturer', fields = ["manufacturer", "manufacturer_part_no", "item_code"])
 	manufacture_details = frappe._dict()
 	for detail in details:
-		dic = manufacture_details.setdefault(detail.get('parent'), {})
+		dic = manufacture_details.setdefault(detail.get('item_code'), {})
 		dic.setdefault('manufacturer', []).append(detail.get('manufacturer'))
 		dic.setdefault('manufacturer_part', []).append(detail.get('manufacturer_part_no'))