fix: add purchase invoice as well

(cherry picked from commit 1fc2edd)

Author: mihir-kandoi

erpnext/stock/doctype/serial_and_batch_bundle/serial_and_batch_bundle.py

@@ -1032,7 +1032,7 @@ def get_qty_field(self, row, qty_field=None) -> str:
 			qty_field = "consumed_qty"
 		elif row.get("doctype") == "Stock Entry Detail":
 			qty_field = "transfer_qty"
-		elif row.get("doctype") == "Sales Invoice Item":
+		elif row.get("doctype") in ["Sales Invoice Item", "Purchase Invoice Item"]:
 			qty_field = "stock_qty"
 
 		return qty_field