Fix: Update changelog

Signed-off-by: Bhumika Sharma <[email protected]>

Author: Bhumika Sharma

CHANGELOG.md

@@ -41,6 +41,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Added File Cache Pinning ([#17617](https://github.com/opensearch-project/OpenSearch/issues/13648))
 - Support consumer reset in Resume API for pull-based ingestion. This PR includes a breaking change for the experimental pull-based ingestion feature. ([#18332](https://github.com/opensearch-project/OpenSearch/pull/18332))
 - Add FIPS build tooling ([#4254](https://github.com/opensearch-project/security/issues/4254))
+- Added node-left metric to cluster manager ([#18421](https://github.com/opensearch-project/OpenSearch/pull/18421))
 
 ### Changed
 - Create generic DocRequest to better categorize ActionRequests ([#18269](https://github.com/opensearch-project/OpenSearch/pull/18269)))