Flip batched execution flag to false for test (elastic#126228)

Disabling this to illustrate a point in nightly ccs runs.

Author: original-brownbear

server/src/main/java/org/elasticsearch/search/SearchService.java

@@ -45,7 +45,6 @@
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.common.util.CollectionUtils;
-import org.elasticsearch.common.util.FeatureFlag;
 import org.elasticsearch.common.util.concurrent.AbstractRunnable;
 import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
 import org.elasticsearch.common.util.concurrent.EsExecutors;
@@ -283,7 +282,7 @@ public class SearchService extends AbstractLifecycleComponent implements IndexEv
         Property.NodeScope
     );
 
-    private static final boolean BATCHED_QUERY_PHASE_FEATURE_FLAG = new FeatureFlag("batched_query_phase").isEnabled();
+    private static final boolean BATCHED_QUERY_PHASE_FEATURE_FLAG = false;
 
     /**
      * The size of the buffer used for memory accounting.