### CI Link

https://gradle-enterprise.elastic.co/s/752jgoui6up4c/tests/:x-pack:plugin:spatial:test/org.elasticsearch.xpack.spatial.index.query.H3LatLonGeometryTests/testIndexPoints?top-execution=1

### Repro line

`./gradlew ':x-pack:plugin:spatial:test' --tests "org.elasticsearch.xpack.spatial.index.query.H3LatLonGeometryTests.testIndexPoints" -Dtests.seed=DFC1C0965EFCD1EB -Dtests.locale=sr-CS -Dtests.timezone=ECT -Druntime.java=17`

Also failed with various other seeds:
* `-Dtests.seed=DFC1C0965EFCD1EB`
* `-Dtests.seed=72BEB29AA48F2C0B`
* `-Dtests.seed=CAF2A0770CD2CC7E`

### Does it reproduce?

Yes

### Applicable branches

main

### Failure history

https://gradle-enterprise.elastic.co/scans/tests?search.timeZoneId=Europe/Stockholm&tests.container=org.elasticsearch.xpack.spatial.index.query.H3LatLonGeometryTests&tests.test=testIndexPoints

### Failure excerpt

    java.lang.AssertionError: expected:<81> but was:<82>
x-pack/plugin/spatial/src/test/java/org/elasticsearch/xpack/spatial/index/query/H3LatLonGeometryTests.java
private static final String FIELD_NAME = "field";
    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/89868")
    public void testIndexPoints() throws Exception {
        Point queryPoint = GeometryTestUtils.randomPoint();
        String[] hexes = new String[H3.MAX_H3_RES + 1];
        for (int res = 0; res < hexes.length; res++) {
            hexes[res] = H3.geoToH3Address(queryPoint.getLat(), queryPoint.getLon(), res);
        }
        IndexWriterConfig iwc = newIndexWriterConfig();
        
        iwc.setMergeScheduler(new SerialMergeScheduler());
        
        iwc.setMaxBufferedDocs(10);
        Directory dir = newDirectory();
        
        int[] counts = new int[H3.MAX_H3_RES + 1];
        IndexWriter w = new IndexWriter(dir, iwc);
        for (String hex : hexes) {
            CellBoundary cellBoundary = H3.h3ToGeoBoundary(hex);
            for (int i = 0; i < cellBoundary.numPoints(); i++) {
                Document doc = new Document();
                LatLng latLng = cellBoundary.getLatLon(i);
                doc.add(new LatLonPoint(FIELD_NAME, latLng.getLatDeg(), latLng.getLonDeg()));
                w.addDocument(doc);
                computeCounts(hexes, latLng.getLonDeg(), latLng.getLatDeg(), counts);
            }
        }
        final int numDocs = randomIntBetween(1000, 2000);
        for (int id = 0; id < numDocs; id++) {