Mute org.elasticsearch.xpack.esql.qa.mixed.MixedClusterEsqlSpecIT test {date.IN operator with null in list, finds match ASYNC} elastic#121491

Author: elasticsearchmachine

muted-tests.yml

@@ -513,3 +513,6 @@ tests:
 - class: org.elasticsearch.backwards.MixedClusterClientYamlTestSuiteIT
   method: test {p0=mtermvectors/10_basic/Tests catching other exceptions per item}
   issue: https://github.com/elastic/elasticsearch/issues/122414
+- class: org.elasticsearch.xpack.esql.qa.mixed.MixedClusterEsqlSpecIT
+  method: test {date.IN operator with null in list, finds match ASYNC}
+  issue: https://github.com/elastic/elasticsearch/issues/121491