changelog: add notes about closing #5968

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### New Features
 * **Alerting**: Adds support for Google Hangouts Chat notifications [#11221](https://github.com/grafana/grafana/issues/11221), thx [@PatrickSchuster](https://github.com/PatrickSchuster)
+* **Elasticsearch**: Support bucket script pipeline aggregations [#5968](https://github.com/grafana/grafana/issues/5968)
 * **Snapshots**: Enable deletion of public snapshot [#14109](https://github.com/grafana/grafana/issues/14109)
 
 ### Minor