Fix link to Release Train docs (really)

Author: priteau

doc/source/operations/rocky-linux-9.rst

@@ -148,9 +148,9 @@ Elasticsearch/Kibana should be migrated to OpenSearch.
 Sync Release Train artifacts
 ----------------------------
 
-New `StackHPC Release Train <../configuration/release-train>`__ content should
-be synced to the local Pulp server. This includes host packages (Deb/RPM) and
-container images.
+New `StackHPC Release Train <../configuration/release-train.html>`__ content
+should be synced to the local Pulp server. This includes host packages
+(Deb/RPM) and container images.
 
 To sync host packages: