Removing the vec file extension from INDEX_STORE_HYBRID_NIO_EXTENSIONS, to ensure the no performance degradation for vector search via Lucene Engine.

Signed-off-by: Navneet Verma <navneev@amazon.com>

Author: navneet1v

CHANGELOG.md

@@ -154,6 +154,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Rethrow OpenSearch exception for non-concurrent path while using concurrent search ([#9177](https://github.com/opensearch-project/OpenSearch/pull/9177))
 - Improve performance of encoding composite keys in multi-term aggregations ([#9412](https://github.com/opensearch-project/OpenSearch/pull/9412))
 - Fix sort related ITs for concurrent search ([#9177](https://github.com/opensearch-project/OpenSearch/pull/9466)
+- Removing the vec file extension from INDEX_STORE_HYBRID_NIO_EXTENSIONS, to ensure the no performance degradation for vector search via Lucene Engine.([#9528](https://github.com/opensearch-project/OpenSearch/pull/9528)))
 
 ### Deprecated
 

server/src/main/java/org/opensearch/index/IndexModule.java

@@ -223,7 +223,6 @@ public Iterator<Setting<?>> settings() {
             "tvd",
             "liv",
             "dii",
-            "vec",
             "vem"
         ),
         Function.identity(),