Remove put settings API capability and replace with node feature.

Author: jbaiera

modules/data-streams/src/yamlRestTest/resources/rest-api-spec/test/data_stream/220_failure_store_cluster_setting.yml

@@ -1,6 +1,7 @@
 setup:
   - requires:
-      reason: "Data stream options was added in 8.18+"
+      cluster_features: [ "data_stream.failure_store" ]
+      reason: "Failure store GA in 8.19+"
       test_runner_features: [ capabilities, allowed_warnings, contains ]
       capabilities:
         - method: POST
@@ -9,9 +10,6 @@ setup:
         - method: POST
           path: /_index_template/{template}
           capabilities: [ 'failure_store_in_template' ]
-        - method: PUT
-          path: /_cluster/settings
-          capabilities: [ 'data_stream_failure_store_cluster_setting' ]
 
   - do:
       cluster.put_settings:

server/src/main/java/org/elasticsearch/rest/action/admin/cluster/RestClusterUpdateSettingsAction.java

@@ -11,7 +11,6 @@
 
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.elasticsearch.client.internal.node.NodeClient;
-import org.elasticsearch.cluster.metadata.DataStream;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
@@ -34,9 +33,6 @@ public class RestClusterUpdateSettingsAction extends BaseRestHandler {
     private static final String PERSISTENT = "persistent";
     private static final String TRANSIENT = "transient";
 
-    // TODO: Remove this and use a single cluster feature / capability for the whole failure store feature when the feature flag is removed
-    private static final String DATA_STREAM_FAILURE_STORE_CLUSTER_SETTING_CAPABILITY = "data_stream_failure_store_cluster_setting";
-
     @Override
     public List<Route> routes() {
         return List.of(new Route(PUT, "/_cluster/settings"));
@@ -78,8 +74,4 @@ public boolean canTripCircuitBreaker() {
         return false;
     }
 
-    @Override
-    public Set<String> supportedCapabilities() {
-        return DataStream.isFailureStoreFeatureFlagEnabled() ? Set.of(DATA_STREAM_FAILURE_STORE_CLUSTER_SETTING_CAPABILITY) : Set.of();
-    }
 }