Update changelog

Signed-off-by: Bruce Hong <bruce.hong@glean.com>

Author: bruce-hong-glean

CHANGELOG.md

@@ -22,7 +22,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Fix flaky tests in CloseIndexIT by addressing cluster state synchronization issues ([#18878](https://github.com/opensearch-project/OpenSearch/issues/18878))
 - [Tiered Caching] Handle  query execution exception ([#19000](https://github.com/opensearch-project/OpenSearch/issues/19000))
 - Grant access to testclusters dir for tests ([#19085](https://github.com/opensearch-project/OpenSearch/issues/19085))
-- Throw error when unrecognized content token type is being indexed ([#19097](https://github.com/opensearch-project/OpenSearch/pull/19097))
 
 ### Dependencies
 - Bump `com.netflix.nebula.ospackage-base` from 12.0.0 to 12.1.0 ([#19019](https://github.com/opensearch-project/OpenSearch/pull/19019))