Mute CATEGORIZE tests also in SYNC tests (elastic#115316)

The test is already muted on main, but now it's causing bwc tests to
fail for backports to 8.x as well.

Author: alex-spies

muted-tests.yml

@@ -309,6 +309,9 @@ tests:
 - class: org.elasticsearch.xpack.esql.qa.mixed.MixedClusterEsqlSpecIT
   method: test {categorize.Categorize ASYNC}
   issue: https://github.com/elastic/elasticsearch/issues/113721
+- class: org.elasticsearch.xpack.esql.qa.mixed.MixedClusterEsqlSpecIT
+  method: test {categorize.Categorize SYNC}
+  issue: https://github.com/elastic/elasticsearch/issues/113722
 - class: org.elasticsearch.action.search.SearchQueryThenFetchAsyncActionTests
   method: testMinimumVersionSameAsNewVersion
   issue: https://github.com/elastic/elasticsearch/issues/114593