fix test

Author: ywangd

modules/repository-s3/src/test/java/org/elasticsearch/repositories/s3/S3ClientsManagerTests.java

@@ -298,7 +298,8 @@ public void testClientsHolderAfterManagerClosed() {
         final ProjectId projectId = randomUniqueProjectId();
         final String clientName = randomFrom(clientNames);
 
-        s3ClientsManager.close();
+        s3Service.close();
+        assertTrue(s3ClientsManager.isManagerClosed());
         // New holder can be added after the manager is closed, but no actual client can be created
         updateProjectInClusterState(projectId, newProjectClientsSecrets(projectId, clientName));
         try (var clientsHolder = s3ClientsManager.getPerProjectClientsHolders().get(projectId)) {