Fix changelog

Author: dnhatn

docs/changelog/125060.yaml

@@ -11,6 +11,6 @@ breaking:
     In earlier versions of {es}, ES|QL would fail the entire query if it encountered any error. ES|QL now returns partial results instead of failing when encountering errors.
 
   impact: >-
-    Callers should check the `partial_results` flag returned in the response to determine if the result is partial or complete. If returning partial results is not desired, this option can be overridden per request via an `allow_partial_results` parameter in the query URL or globally via the cluster setting `esql.query.allow_partial_results`.
+    Callers should check the `is_partial` flag returned in the response to determine if the result is partial or complete. If returning partial results is not desired, this option can be overridden per request via an `allow_partial_results` parameter in the query URL or globally via the cluster setting `esql.query.allow_partial_results`.
 
   notable: true