Fix SearchableSnapshotDirectoryTests.testIndexSearcher() (#56275)

Closes #56233

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/index/store/BaseSearchableSnapshotIndexInput.java

@@ -145,7 +145,8 @@ public abstract class BaseSearchableSnapshotIndexInput extends BufferedIndexInpu
 
             // Unit tests access the blob store on the main test thread; simplest just to permit this rather than have them override this
             // method somehow.
-            || threadName.startsWith("TEST-") : "current thread [" + Thread.currentThread() + "] may not read " + fileInfo;
+            || threadName.startsWith("TEST-")
+            || threadName.startsWith("LuceneTestCase") : "current thread [" + Thread.currentThread() + "] may not read " + fileInfo;
         return true;
     }
 

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/SearchableSnapshotDirectoryTests.java

@@ -138,7 +138,6 @@ public class SearchableSnapshotDirectoryTests extends ESTestCase {
         );
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/56233")
     public void testIndexSearcher() throws Exception {
         testDirectories((directory, snapshotDirectory) -> {
             try (DirectoryReader reader = DirectoryReader.open(directory)) {