HSEARCH-5276 Upgrade Elasticsearch client to 8.15.4

build/parents/build/pom.xml

@@ -48,7 +48,7 @@
         <!-- >>> Elasticsearch -->
         <!-- The version of the Elasticsearch client used by Hibernate Search, independently of the version of the remote cluster -->
         <!-- Use the latest open-source version here. Currently, low-level clients are open-source even in 8.5+ -->
-        <version.org.elasticsearch.client>8.15.2</version.org.elasticsearch.client>
+        <version.org.elasticsearch.client>8.15.4</version.org.elasticsearch.client>
         <!-- The main compatible version of Elasticsearch, advertised by default. Used in documentation links. -->
         <version.org.elasticsearch.compatible.main>${version.org.elasticsearch.latest}</version.org.elasticsearch.compatible.main>
         <documentation.org.elasticsearch.url>https://www.elastic.co/guide/en/elasticsearch/reference/${parsed-version.org.elasticsearch.compatible.main.majorVersion}.${parsed-version.org.elasticsearch.compatible.main.minorVersion}</documentation.org.elasticsearch.url>