Mute failing test (#56283)

see: #56282

x-pack/plugin/ml/qa/native-multi-node-tests/src/test/java/org/elasticsearch/xpack/ml/integration/RegressionIT.java

@@ -169,7 +169,8 @@ public class RegressionIT extends MlNativeDataFrameAnalyticsIntegTestCase {
             "Started writing results",
             "Finished analysis");
     }
-
+    
+    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/56282")
     public void testWithOnlyTrainingRowsAndTrainingPercentIsFifty() throws Exception {
         initialize("regression_only_training_data_and_training_percent_is_50");
         String predictedClassField = DEPENDENT_VARIABLE_FIELD + "_prediction";