[Serverless][Security Solution][Endpoint] Re-enable execute API ftr t…

…est (elastic#172134)

## Summary

Re-enable execute API ftr test

**Flakey runner**
-
https://buildkite.com/elastic/kibana-flaky-test-suite-runner/builds/4090
x 100 ( all pass )

### Checklist

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

x-pack/test/security_solution_endpoint_api_int/apis/endpoint_response_actions/execute.ts

@@ -16,9 +16,7 @@ export default function ({ getService }: FtrProviderContext) {
   const supertestWithoutAuth = getService('supertestWithoutAuth');
   const endpointTestResources = getService('endpointTestResources');
 
-  // FLAKY: https://github.com/elastic/kibana/issues/171667
-  // FLAKY: https://github.com/elastic/kibana/issues/171666
-  describe.skip('Endpoint `execute` response action', function () {
+  describe('Endpoint `execute` response action', function () {
     targetTags(this, ['@ess', '@serverless']);
 
     let indexedData: IndexedHostsAndAlertsResponse;