Mute RegressionIT.testAliasFields test (#63339)

It fails quite frequently in 7.x.

Relates to #63268

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

@@ -481,6 +481,7 @@ public class RegressionIT extends MlNativeDataFrameAnalyticsIntegTestCase {
             "Finished analysis");
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/63268")
     public void testAliasFields() throws Exception {
         // The goal of this test is to assert alias fields are included in the analytics job.
         // We have a simple dataset with two integer fields: field_1 and field_2.