[CI] Mute 110_max_metric (#89997)

For #89994

Author: davidkyle

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.aggregation/110_max_metric.yml

@@ -207,9 +207,9 @@ setup:
 ---
 "Merging results with unmapped fields":
   - skip:
-      version: " - 8.3.99"
-      reason: Fixed in 8.4.0
-      
+      version: "all"
+      reason: "https://github.com/elastic/elasticsearch/issues/89994"
+
   - do:
      search:
        index: [date_test_1, date_test_2]