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
Thread[] searchers = new Thread[randomIntBetween(1, 4)];
        CountDownLatch latch = new CountDownLatch(searchers.length);
        for (int i = 0; i < searchers.length; i++) {
            searchers[i] = new Thread(() -> {
                latch.countDown();
                while (stopped.get() == false) {
                    try {
                        client().prepareSearch("test").setRequestCache(false).get();
                    } catch (Exception ignored) {
                        return;
                    }
                }
            });
            searchers[i].start();
        }
        latch.await();
        indicesAdmin().prepareDelete("test").get();
        stopped.set(true);
        for (Thread searcher : searchers) {
            searcher.join();
        }
    }
    public void testLookUpSearchContext() throws Exception {
        createIndex("index");
        SearchService searchService = getInstanceFromNode(SearchService.class);
        IndicesService indicesService = getInstanceFromNode(IndicesService.class);
        IndexService indexService = indicesService.indexServiceSafe(resolveIndex("index"));
        IndexShard indexShard = indexService.getShard(0);
        List<ShardSearchContextId> contextIds = new ArrayList<>();
        int numContexts = randomIntBetween(1, 10);