fix(manufacturing): set sales order references in subassembly child table

(cherry picked from commit 0f2ed28)

Author: Sudharsanan11

erpnext/manufacturing/doctype/production_plan/production_plan.py

@@ -844,6 +844,8 @@ def prepare_data_for_sub_assembly_items(self, row, wo_data):
 			"stock_uom",
 			"bom_level",
 			"schedule_date",
+			"sales_order",
+			"sales_order_item",
 		]:
 			if row.get(field):
 				wo_data[field] = row.get(field)
@@ -898,6 +900,8 @@ def calculate_sub_assembly_items():
 					"qty",
 					"description",
 					"production_plan_item",
+					"sales_order",
+					"sales_order_item",
 				]:
 					po_data[field] = row.get(field)
 
@@ -1122,6 +1126,10 @@ def set_sub_assembly_items_based_on_level(self, row, bom_data, manufacturing_typ
 			if not is_group_warehouse:
 				data.fg_warehouse = self.sub_assembly_warehouse
 
+			if not self.combine_sub_items:
+				data.sales_order = row.sales_order
+				data.sales_order_item = row.sales_order_item
+
 	def set_default_supplier_for_subcontracting_order(self):
 		items = [
 			d.production_item for d in self.sub_assembly_items if d.type_of_manufacturing == "Subcontract"