ES|QL: Fix funciton Telemetry tests (elastic#116470)

Author: luigidellaquila

x-pack/plugin/src/yamlRestTest/resources/rest-api-spec/test/esql/60_usage.yml

@@ -162,4 +162,4 @@ setup:
   - match: {esql.functions.cos: $functions_cos}
   - gt: {esql.functions.to_long: $functions_to_long}
   - match: {esql.functions.coalesce: $functions_coalesce}
-  - length: {esql.functions: 118} # check the "sister" test above for a likely update to the same esql.functions length check
+  - length: {esql.functions: 116} # check the "sister" test above for a likely update to the same esql.functions length check