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
client().execute(
            InternalOrPrivateSettingsPlugin.UpdateInternalOrPrivateAction.INSTANCE,
            new InternalOrPrivateSettingsPlugin.UpdateInternalOrPrivateAction.Request(
                "throttled_threadpool_index",
                IndexSettings.INDEX_SEARCH_THROTTLED.getKey(),
                "false"
            )
        ).actionGet();
        IllegalArgumentException iae = expectThrows(
            IllegalArgumentException.class,
            () -> indicesAdmin().prepareUpdateSettings("throttled_threadpool_index")
                .setSettings(Settings.builder().put(IndexSettings.INDEX_SEARCH_THROTTLED.getKey(), false))
                .get()
        );
        assertEquals("can not update private setting [index.search.throttled]; this setting is managed by Elasticsearch", iae.getMessage());
        assertFalse(service.getIndicesService().indexServiceSafe(index).getIndexSettings().isSearchThrottled());
        SearchRequest searchRequest = new SearchRequest().allowPartialSearchResults(false);
        ShardSearchRequest req = new ShardSearchRequest(
            OriginalIndices.NONE,
            searchRequest,
            new ShardId(index, 0),
            0,
            1,
            AliasFilter.EMPTY,
            1f,
            -1,
            null
        );
        Thread currentThread = Thread.currentThread();