Fix CHANGELOG.md entry (opensearch-project#20500)

Signed-off-by: Andriy Redko <drreta@gmail.com>

Author: reta

CHANGELOG.md

@@ -24,8 +24,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add X-Request-Id to uniquely identify a search request ([#19798](https://github.com/opensearch-project/OpenSearch/pull/19798))
 - Added TopN selection logic for streaming terms aggregations ([#20481](https://github.com/opensearch-project/OpenSearch/pull/20481))
 - Added support for Intra Segment Search ([#19704](https://github.com/opensearch-project/OpenSearch/pull/19704))
-
-- Introduce CodecRegistry and EnginePlugin::getAdditionalCodecs hook to allow additional Codec registration ([#20411](https://github.com/opensearch-project/OpenSearch/pull/20411))
 - Introduce AdditionalCodecs and EnginePlugin::getAdditionalCodecs hook to allow additional Codec registration ([#20411](https://github.com/opensearch-project/OpenSearch/pull/20411))
 
 ### Changed