### 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/main/java/org/elasticsearch/xpack/spatial/index/query/H3LatLonGeometry.java
double maxY,
            double aX,
            double aY,
            boolean ab,
            double bX,
            double bY
        ) {
            throw new UnsupportedOperationException("withinLine not implemented in H3Polygon2D");
        }
        @Override
        public WithinRelation withinTriangle(
            double minX,
            double maxX,
            double minY,
            double maxY,
            double aX,
            double aY,
            boolean ab,
            double bX,
            double bY,
            boolean bc,
            double cX,
            double cY,
            boolean ca
        ) {
            throw new UnsupportedOperationException("withinTriangle not implemented in H3Polygon2D");
        }
    }
}