fix: ignore perm level validation if row deleted (#18290) (#18292)

(cherry picked from commit bd21398252)

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/model/base_document.py

@@ -1175,7 +1175,10 @@ class BaseDocument:
 				# get values from old doc
 				if self.get("parent_doc"):
 					parent_doc = self.parent_doc.get_latest()
-					ref_doc = [d for d in parent_doc.get(self.parentfield) if d.name == self.name][0]
+					child_docs = [d for d in parent_doc.get(self.parentfield) if d.name == self.name]
+					if not child_docs:
+						return
+					ref_doc = child_docs[0]
 				else:
 					ref_doc = self.get_latest()