### CI Link

https://gradle-enterprise.elastic.co/s/oyi6h23yl6k3o/tests/:x-pack:qa:full-cluster-restart:v8.11.0%23bwcTest/org.elasticsearch.xpack.restart.CoreFullClusterRestartIT/testClusterState%20%7Bcluster=OLD%7D

### Repro line

./gradlew ':qa:full-cluster-restart:v8.11.0#bwcTest' -Dtests.class="org.elasticsearch.upgrades.FullClusterRestartIT"

### Does it reproduce?

Yes

### Applicable branches

main

### Failure history

_No response_

### Failure excerpt

This test assumes that the index created version in cluster state matches the old node version.

That is no longer true due to the introduction of `IndexVersion`

https://github.com/elastic/elasticsearch/blob/52a6820813577abcb23191d862a01e32e652ed42/qa/full-cluster-restart/src/javaRestTest/java/org/elasticsearch/upgrades/FullClusterRestartIT.java#L435-L440
qa/full-cluster-restart/src/javaRestTest/java/org/elasticsearch/upgrades/FullClusterRestartIT.java
restoreCommand.endObject();
        Request restoreRequest = new Request("POST", "/_snapshot/repo/" + snapshotName + "/_restore");
        restoreRequest.addParameter("wait_for_completion", "true");
        restoreRequest.setJsonEntity(Strings.toString(restoreCommand));
        client().performRequest(restoreRequest);
        
        Request countRequest = new Request("GET", "/restored_" + index + "/_search");
        countRequest.addParameter("size", "0");
        Map<String, Object> countResponse = entityAsMap(client().performRequest(countRequest));
        assertTotalHits(count, countResponse);
        
        int extras = between(1, 100);
        StringBuilder bulk = new StringBuilder();
        for (int i = 0; i < extras; i++) {
            bulk.append(Strings.format("""
                {"index":{"_id":"%s"}}
                {"test":"test"}
                """, count + i));
        }
        Request writeToRestoredRequest = new Request("POST", "/restored_" + index + "/_bulk");
        writeToRestoredRequest.addParameter("refresh", "true");
        writeToRestoredRequest.setJsonEntity(bulk.toString());
        assertThat(EntityUtils.toString(client().performRequest(writeToRestoredRequest).getEntity()), containsString("\"errors\":false"));
        
        
        Request countAfterWriteRequest = new Request("GET", "/restored_" + index + "/_search");
        countAfterWriteRequest.addParameter("size", "0");
        Map<String, Object> countAfterResponse = entityAsMap(client().performRequest(countRequest));
        assertTotalHits(count + extras, countAfterResponse);