SearchServiceTests.testIsParallelCollectionSupportedForResults fails intermittently

```
12:37:10 org.elasticsearch.search.SearchServiceTests > testIsParallelCollectionSupportedForResults FAILED
12:37:10     java.lang.AssertionError
12:37:10         at __randomizedtesting.SeedInfo.seed([4140C168DE8FB0BB:771A78D5E4B36180]:0)
12:37:10         at org.junit.Assert.fail(Assert.java:86)
12:37:10         at org.junit.Assert.assertTrue(Assert.java:41)
12:37:10         at org.junit.Assert.assertFalse(Assert.java:64)
12:37:10         at org.junit.Assert.assertFalse(Assert.java:74)
12:37:10         at org.elasticsearch.search.SearchServiceTests.testIsParallelCollectionSupportedForResults(SearchServiceTests.java:2096)
```

```
./gradlew ':server:test' --tests "org.elasticsearch.search.SearchServiceTests.testIsParallelCollectionSupportedForResults" -Dtests.seed=4140C168DE8FB0BB -Dtests.locale=es-SV -Dtests.timezone=Africa/Banjul -Druntime.java=20
```
server/src/test/java/org/elasticsearch/search/SearchServiceTests.java
+ SearchService.MAX_OPEN_SCROLL_CONTEXT.get(Settings.EMPTY)
                + "]. "
                + "This limit can be set by changing the [search.max_open_scroll_context] setting.",
            ex.getMessage()
        );
        service.freeAllScrollContexts();
    }
    public void testOpenScrollContextsConcurrently() throws Exception {
        createIndex("index");
        final IndicesService indicesService = getInstanceFromNode(IndicesService.class);
        final IndexService indexService = indicesService.indexServiceSafe(resolveIndex("index"));
        final IndexShard indexShard = indexService.getShard(0);
        final int maxScrollContexts = SearchService.MAX_OPEN_SCROLL_CONTEXT.get(Settings.EMPTY);
        final SearchService searchService = getInstanceFromNode(SearchService.class);
        Thread[] threads = new Thread[randomIntBetween(2, 8)];
        CountDownLatch latch = new CountDownLatch(threads.length);
        for (int i = 0; i < threads.length; i++) {
            threads[i] = new Thread(() -> {
                latch.countDown();
                try {
                    latch.await();
                    for (;;) {
                        final Engine.SearcherSupplier reader = indexShard.acquireSearcherSupplier();
                        try {
                            final ShardScrollRequestTest request = new ShardScrollRequestTest(indexShard.shardId());
                            searchService.createAndPutReaderContext(
                                request,
                                indexService,
                                indexShard,
                                reader,