[TEST] Don't expect acks when isolating nodes

With #30672, acking expects *all* nodes to successfully apply the cluster state.
The testElectMasterWithLatestVersion test was checking for an ack while isolating
one node in the test.

Relates to #30672

server/src/test/java/org/elasticsearch/discovery/DiscoveryDisruptionIT.java

@@ -53,7 +53,6 @@
 
 import static org.elasticsearch.cluster.metadata.IndexMetaData.INDEX_NUMBER_OF_REPLICAS_SETTING;
 import static org.elasticsearch.cluster.metadata.IndexMetaData.INDEX_NUMBER_OF_SHARDS_SETTING;
-import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 
 /**
@@ -256,8 +255,8 @@ public void testElectMasterWithLatestVersion() throws Exception {
         internalCluster().setDisruptionScheme(isolatePreferredMaster);
         isolatePreferredMaster.startDisrupting();
 
-        assertAcked(client(randomFrom(nonPreferredNodes)).admin().indices().prepareCreate("test").setSettings(
-            Settings.builder().put(INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1).put(INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 0)));
+        client(randomFrom(nonPreferredNodes)).admin().indices().prepareCreate("test").setSettings(
+            Settings.builder().put(INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1).put(INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 0)).get();
 
         internalCluster().clearDisruptionScheme(false);
         internalCluster().setDisruptionScheme(isolateAllNodes);