Mute org.elasticsearch.xpack.esql.action.CrossClustersCancellationIT testCancelSkipUnavailable elastic#121631

Author: elasticsearchmachine

muted-tests.yml

@@ -539,3 +539,6 @@ tests:
 - class: org.elasticsearch.xpack.esql.action.CrossClustersCancellationIT
   method: testCloseSkipUnavailable
   issue: https://github.com/elastic/elasticsearch/issues/121627
+- class: org.elasticsearch.xpack.esql.action.CrossClustersCancellationIT
+  method: testCancelSkipUnavailable
+  issue: https://github.com/elastic/elasticsearch/issues/121631