### 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
templateBuilder.startObject("alias1").endObject();
            templateBuilder.startObject("alias2");
            {
                templateBuilder.startObject("filter");
                {
                    templateBuilder.startObject("term");
                    {
                        templateBuilder.field("version", isRunningAgainstOldCluster() ? getOldClusterVersion() : Version.CURRENT);
                    }
                    templateBuilder.endObject();
                }
                templateBuilder.endObject();
            }
            templateBuilder.endObject();
        }
        templateBuilder.endObject().endObject();
        Request createTemplateRequest = new Request("PUT", "/_template/test_template");
        createTemplateRequest.setJsonEntity(Strings.toString(templateBuilder));
        createTemplateRequest.setOptions(expectWarnings(RestPutIndexTemplateAction.DEPRECATION_WARNING));
        client().performRequest(createTemplateRequest);
        if (isRunningAgainstOldCluster()) {
            
            XContentBuilder repoConfig = JsonXContent.contentBuilder().startObject();
            {
                repoConfig.field("type", "fs");
                repoConfig.startObject("settings");
                {
                    repoConfig.field("compress", randomBoolean());
                    repoConfig.field("location", repoDirectory.getRoot().getPath());
                }