fix(subcontracting): savepoint Purchase Receipt submit in make_purchase_receipt (Postgres)

Same submit()/add_comment-in-except shape as the PO->SCO mapper: on Postgres a failed submit aborts the transaction so the follow-on Comment insert raises InFailedSqlTransaction; MariaDB continues. Savepoint + rollback before add_comment. No-op on MariaDB.

erpnext/subcontracting/doctype/subcontracting_receipt/mapper.py

@@ -125,9 +125,11 @@ def make_purchase_receipt(
 		target_doc.save()
 
 		if submit and frappe.has_permission(target_doc.doctype, "submit", target_doc):
+			frappe.db.savepoint("submit_subcontracting_receipt")
 			try:
 				target_doc.submit()
 			except Exception as e:
+				frappe.db.rollback(save_point="submit_subcontracting_receipt")
 				target_doc.add_comment("Comment", _("Submit Action Failed") + "<br><br>" + str(e))
 
 		if notify: