Fix length assertion

Author: przemekwitek

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

@@ -39,7 +39,7 @@ setup:
   - do: {xpack.usage: {}}
   - match: { esql.available: true }
   - match: { esql.enabled: true }
-  - length: { esql.features: 16 }
+  - length: { esql.features: 15 }
   - set: {esql.features.dissect: dissect_counter}
   - set: {esql.features.drop: drop_counter}
   - set: {esql.features.eval: eval_counter}
@@ -117,7 +117,7 @@ setup:
   - do: {xpack.usage: {}}
   - match: { esql.available: true }
   - match: { esql.enabled: true }
-  - length: { esql.features: 16 }
+  - length: { esql.features: 15 }
   - set: {esql.features.dissect: dissect_counter}
   - set: {esql.features.drop: drop_counter}
   - set: {esql.features.eval: eval_counter}