patch: Set against_blanket_order value in existing SO/PO (#19810)

* patch: Set against_blanket_order value in existing SO/PO

* Update set_against_blanket_order_in_sales_and_purchase_order.py
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index daedca7..68b6cc0 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -647,4 +647,5 @@
 erpnext.patches.v12_0.set_default_for_add_taxes_from_item_tax_template
 erpnext.patches.v12_0.remove_denied_leaves_from_leave_ledger
 erpnext.patches.v12_0.update_price_or_product_discount
-erpnext.patches.v12_0.set_production_capacity_in_workstation
\ No newline at end of file
+erpnext.patches.v12_0.set_production_capacity_in_workstation
+erpnext.patches.v12_0.set_against_blanket_order_in_sales_and_purchase_order
\ No newline at end of file