fix: ignore mandatory fields while creating WO from SO (#28772)

If fields are made mandatory from customizations the WO creation simply
fails.
diff --git a/erpnext/selling/doctype/sales_order/sales_order.py b/erpnext/selling/doctype/sales_order/sales_order.py
index 1c24825..e69e28d 100755
--- a/erpnext/selling/doctype/sales_order/sales_order.py
+++ b/erpnext/selling/doctype/sales_order/sales_order.py
@@ -978,6 +978,7 @@
 			description=i['description']
 		)).insert()
 		work_order.set_work_order_operations()
+		work_order.flags.ignore_mandatory = True
 		work_order.save()
 		out.append(work_order)