fix(cases-analytics-v2): drop unused supertest in analytics_v2_off integration test

Triggers tsc error TS6133 'supertest is declared but its value is
never read'. The test only exercises supertestWithoutAuth + es; the
supertest binding was a scaffold leftover. No behavior change.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: michaelolo24

x-pack/platform/test/cases_api_integration/spaces_only/tests/trial/analytics_v2_off.ts

@@ -30,7 +30,6 @@ import {
  * "deployments not using v2 are untouched" promise.
  */
 export default ({ getService }: FtrProviderContext): void => {
-  const supertest = getService('supertest');
   const supertestWithoutAuth = getService('supertestWithoutAuth');
   const es = getService('es');
   const auth = getAuthWithSuperUser();