### 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
count = randomIntBetween(2000, 3000);
            byte[] randomByteArray = new byte[16];
            random().nextBytes(randomByteArray);
            indexRandomDocuments(
                count,
                true,
                true,
                randomBoolean(),
                i -> JsonXContent.contentBuilder()
                    .startObject()
                    .field("string", randomAlphaOfLength(10))
                    .field("int", randomInt(100))
                    .field("float", randomFloat())
                    
                    .field("bool", i > 0 && randomBoolean())
                    .field("field.with.dots", randomAlphaOfLength(10))
                    .field("binary", Base64.getEncoder().encodeToString(randomByteArray))
                    .endObject()
            );
            refreshAllIndices();
        } else {
            count = countOfIndexedRandomDocuments();
        }
        ensureGreenLongWait(index);
        assertBasicSearchWorks(count);
        assertAllSearchWorks(count);
        assertBasicAggregationWorks();
        assertRealtimeGetWorks();
        assertStoredBinaryFields(count);
    }