**Build scan:**
https://gradle-enterprise.elastic.co/s/bvb5puxxlbaou/tests/:server:internalClusterTest/org.elasticsearch.action.admin.indices.create.SplitIndexIT/testCreateSplitIndexToN

**Reproduction line:**
```
gradlew ':server:internalClusterTest' --tests "org.elasticsearch.action.admin.indices.create.SplitIndexIT.testCreateSplitIndexToN" -Dtests.seed=24641F2A0356AEBD -Dtests.locale=ar-MA -Dtests.timezone=SystemV/EST5 -Druntime.java=19
```

**Applicable branches:**
8.6

**Reproduces locally?:**
Didn't try

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.action.admin.indices.create.SplitIndexIT&tests.test=testCreateSplitIndexToN

**Failure excerpt:**
```
java.lang.AssertionError: timed out waiting for green state

  at __randomizedtesting.SeedInfo.seed([24641F2A0356AEBD:92C8F9F3E9C1145A]:0)
  at org.junit.Assert.fail(Assert.java:88)
  at org.elasticsearch.test.ESIntegTestCase.ensureColor(ESIntegTestCase.java:966)
  at org.elasticsearch.test.ESIntegTestCase.ensureGreen(ESIntegTestCase.java:905)
  at org.elasticsearch.test.ESIntegTestCase.ensureGreen(ESIntegTestCase.java:894)
  at org.elasticsearch.action.admin.indices.create.SplitIndexIT.splitToN(SplitIndexIT.java:245)
  at org.elasticsearch.action.admin.indices.create.SplitIndexIT.testCreateSplitIndexToN(SplitIndexIT.java:78)
  at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
  at java.lang.reflect.Method.invoke(Method.java:578)
  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:44)
  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:1589)

```
server/src/internalClusterTest/java/org/elasticsearch/action/admin/indices/create/SplitIndexIT.java
logger.info("use routing {} use mixed routing {} use nested {}", useRouting, useMixedRouting, useNested);
        createInitialIndex.setSettings(settings).get();
        int numDocs = randomIntBetween(10, 50);
        String[] routingValue = new String[numDocs];
        BiFunction<String, Integer, IndexRequestBuilder> indexFunc = (index, id) -> {
            try {
                return client().prepareIndex(index)
                    .setId(Integer.toString(id))
                    .setSource(
                        jsonBuilder().startObject()
                            .field("foo", "bar")
                            .field("i", id)
                            .startArray("nested1")
                            .startObject()
                            .field("n_field1", "n_value1_1")
                            .field("n_field2", "n_value2_1")
                            .endObject()
                            .startObject()
                            .field("n_field1", "n_value1_2")
                            .field("n_field2", "n_value2_2")
                            .endObject()
                            .endArray()
                            .endObject()
                    );
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        };
        for (int i = 0; i < numDocs; i++) {
            IndexRequestBuilder builder = indexFunc.apply("source", i);