add missed applyCluster state change

Signed-off-by: Kaushal Kumar <[email protected]>

server/src/main/java/org/opensearch/wlm/QueryGroupService.java

@@ -57,7 +57,7 @@ public class QueryGroupService extends AbstractLifecycleComponent
     private final ThreadPool threadPool;
     private final ClusterService clusterService;
     private final WorkloadManagementSettings workloadManagementSettings;
-    private final Set<QueryGroup> activeQueryGroups;
+    private Set<QueryGroup> activeQueryGroups;
     private final Set<QueryGroup> deletedQueryGroups;
     private final NodeDuressTrackers nodeDuressTrackers;
 
@@ -175,7 +175,6 @@ public void applyClusterState(ClusterChangedEvent event) {
                 // New query group detected
                 QueryGroup newQueryGroup = currentQueryGroups.get(queryGroupName);
                 // Perform any necessary actions with the new query group
-                this.activeQueryGroups.add(newQueryGroup);
                 queryGroupStateMap.put(newQueryGroup.get_id(), new QueryGroupState());
             }
         }
@@ -190,6 +189,7 @@ public void applyClusterState(ClusterChangedEvent event) {
                 queryGroupStateMap.remove(deletedQueryGroup.get_id());
             }
         }
+        this.activeQueryGroups = new HashSet<>(currentMetadata.queryGroups().values());
     }
 
     /**