fix: Validate existing doctype names too

frappe/model/rename_doc.py

@@ -49,9 +49,7 @@ def rename_doc(doctype, old, new, force=False, merge=False, ignore_permissions=F
 	old_doc = frappe.get_doc(doctype, old)
 	out = old_doc.run_method("before_rename", old, new, merge) or {}
 	new = (out.get("new") or new) if isinstance(out, dict) else (out or new)
-
-	if doctype != "DocType":
-		new = validate_rename(doctype, new, meta, merge, force, ignore_permissions)
+	new = validate_rename(doctype, new, meta, merge, force, ignore_permissions)
 
 	if not merge:
 		rename_parent_and_child(doctype, old, new, meta)