[test] Always assume that the old cluster support replication of closed indices (elastic#114314)

Support for replicating closed indices was added in elastic#39506 (7.1.0), we can expect the the cluster always supports replication of closed indices in 8.0/9.0

Author: arteam

qa/full-cluster-restart/src/javaRestTest/java/org/elasticsearch/upgrades/FullClusterRestartIT.java

@@ -27,7 +27,6 @@
 import org.elasticsearch.common.xcontent.support.XContentMapValues;
 import org.elasticsearch.core.Booleans;
 import org.elasticsearch.core.CheckedFunction;
-import org.elasticsearch.core.UpdateForV9;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.IndexVersion;
 import org.elasticsearch.index.IndexVersions;
@@ -1203,15 +1202,8 @@ public void testClosedIndices() throws Exception {
             closeIndex(index);
         }
 
-        @UpdateForV9(owner = UpdateForV9.Owner.DISTRIBUTED_INDEXING) // This check can be removed (always assume true)
-        var originalClusterSupportsReplicationOfClosedIndices = oldClusterHasFeature(RestTestLegacyFeatures.REPLICATION_OF_CLOSED_INDICES);
-
-        if (originalClusterSupportsReplicationOfClosedIndices) {
-            ensureGreenLongWait(index);
-            assertClosedIndex(index, true);
-        } else {
-            assertClosedIndex(index, false);
-        }
+        ensureGreenLongWait(index);
+        assertClosedIndex(index, true);
 
         if (isRunningAgainstOldCluster() == false) {
             openIndex(index);