### 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
mappingsAndSettings.startObject();
            {
                mappingsAndSettings.startObject("settings");
                mappingsAndSettings.field("number_of_shards", 1);
                mappingsAndSettings.field("number_of_replicas", 1);
                if (randomBoolean()) {
                    mappingsAndSettings.field("soft_deletes.enabled", true);
                }
                mappingsAndSettings.endObject();
            }
            mappingsAndSettings.endObject();
            Request createIndex = new Request("PUT", "/" + index);
            createIndex.setJsonEntity(Strings.toString(mappingsAndSettings));
            client().performRequest(createIndex);
            int numDocs = between(10, 100);
            for (int i = 0; i < numDocs; i++) {
                String doc = Strings.toString(JsonXContent.contentBuilder().startObject().field("field", "v1").endObject());
                Request request = new Request("POST", "/" + index + "/_doc/" + i);
                request.setJsonEntity(doc);
                client().performRequest(request);
                refreshAllIndices();
            }
            client().performRequest(new Request("POST", "/" + index + "/_flush"));
            int liveDocs = numDocs;
            assertTotalHits(liveDocs, entityAsMap(client().performRequest(new Request("GET", "/" + index + "/_search"))));
            for (int i = 0; i < numDocs; i++) {
                if (randomBoolean()) {
                    String doc = Strings.toString(JsonXContent.contentBuilder().startObject().field("field", "v2").endObject());
                    Request request = new Request("POST", "/" + index + "/_doc/" + i);
                    request.setJsonEntity(doc);