[ML] Unmute MachineLearningIT.testDeleteExpiredData (#41186)

The cause of failure was fixed by elastic/ml-cpp#459,
so all that remains on the Java side is to unmute the
test that was failing.

Closes #41070

client/rest-high-level/src/test/java/org/elasticsearch/client/MachineLearningIT.java

@@ -915,7 +915,6 @@ public class MachineLearningIT extends ESRestHighLevelClientTestCase {
         return forecastJobResponse.getForecastId();
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/41070")
     public void testDeleteExpiredData() throws Exception {
 
         String jobId = "test-delete-expired-data";