This looks like more fallout from the 8.12 version bump.

**Build scan:**
https://gradle-enterprise.elastic.co/s/iznsqgeozhlcw/tests/:x-pack:qa:rolling-upgrade-multi-cluster:v8.11.0%23follower%23upgradedClusterTest/org.elasticsearch.upgrades.CcrRollingUpgradeIT/testCannotFollowLeaderInUpgradedCluster
**Reproduction line:**
```
./gradlew ':x-pack:qa:rolling-upgrade-multi-cluster:v8.11.0#follower#upgradedClusterTest' -Dtests.class="org.elasticsearch.upgrades.CcrRollingUpgradeIT" -Dtests.method="testCannotFollowLeaderInUpgradedCluster" -Dtests.seed=27E3EAD1DEC83E86 -Dtests.bwc=true -Dtests.locale=sl-SI -Dtests.timezone=America/Caracas -Druntime.java=21
```

**Applicable branches:**
main

**Reproduces locally?:**
Yes

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.upgrades.CcrRollingUpgradeIT&tests.test=testCannotFollowLeaderInUpgradedCluster
**Failure excerpt:**
```
junit.framework.AssertionFailedError: Expected exception ResponseException but no exception was thrown

  at __randomizedtesting.SeedInfo.seed([27E3EAD1DEC83E86:A9BC1A5D74E1259D]:0)
  at org.apache.lucene.tests.util.LuceneTestCase.expectThrows(LuceneTestCase.java:2864)
  at org.apache.lucene.tests.util.LuceneTestCase.expectThrows(LuceneTestCase.java:2850)
  at org.elasticsearch.upgrades.CcrRollingUpgradeIT.testCannotFollowLeaderInUpgradedCluster(CcrRollingUpgradeIT.java:223)
  at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
  at java.lang.reflect.Method.invoke(Method.java:580)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.invoke(RandomizedRunner.java:1758)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$8.evaluate(RandomizedRunner.java:946)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$9.evaluate(RandomizedRunner.java:982)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$10.evaluate(RandomizedRunner.java:996)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleSetupTeardownChained$1.evaluate(TestRuleSetupTeardownChained.java:48)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleThreadAndTestName$1.evaluate(TestRuleThreadAndTestName.java:45)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.forkTimeoutingTask(ThreadLeakControl.java:843)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$3.evaluate(ThreadLeakControl.java:490)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.runSingleTest(RandomizedRunner.java:955)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$5.evaluate(RandomizedRunner.java:840)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$6.evaluate(RandomizedRunner.java:891)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$7.evaluate(RandomizedRunner.java:902)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleStoreClassName$1.evaluate(TestRuleStoreClassName.java:38)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleAssertionsRequired$1.evaluate(TestRuleAssertionsRequired.java:53)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleIgnoreTestSuites$1.evaluate(TestRuleIgnoreTestSuites.java:47)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.lambda$forkTimeoutingTask$0(ThreadLeakControl.java:850)
  at java.lang.Thread.run(Thread.java:1583)

```
x-pack/qa/rolling-upgrade-multi-cluster/src/test/java/org/elasticsearch/upgrades/CcrRollingUpgradeIT.java
break;
                case TWO_THIRD:
                    index(leaderClient(), "leader_index5", 128);
                    break;
                case ALL:
                    ensureGreen(followerClient(), "follower_index5");
                    resumeIndexFollowing(followerClient(), "follower_index5");
                    ensureGreen(leaderClient(), "follower_index6");
                    resumeIndexFollowing(leaderClient(), "follower_index6");
                    assertTotalHitCount("follower_index5", 896, followerClient());
                    assertTotalHitCount("follower_index6", 896, leaderClient());
                    break;
                default:
                    throw new AssertionError("unexpected upgrade_state [" + upgradeState + "]");
            }
        } else {
            throw new AssertionError("unexpected cluster_name [" + clusterName + "]");
        }
    }
    private static void createLeaderIndex(RestClient client, String indexName) throws IOException {
        Settings.Builder indexSettings = indexSettings(1, 0);
        if (randomBoolean()) {
            indexSettings.put("index.soft_deletes.enabled", true);
        }
        createIndex(client, indexName, indexSettings.build());
    }
    private static void followIndex(RestClient client, String leaderCluster, String leaderIndex, String followIndex) throws IOException {
        final Request request = new Request("PUT", "/" + followIndex + "/_ccr/follow?wait_for_active_shards=1");
        request.setJsonEntity(Strings.format("""
            {"remote_cluster": "%s", "leader_index": "%s", "read_poll_timeout": "10ms"}