remove ent-search from 9.0 test (#379)

Author: miguelgrinberg

tests/security/90_service_accounts.yml

@@ -16,7 +16,6 @@ teardown:
       security.get_service_accounts:
         namespace: elastic
   - is_true: "elastic/auto-ops"
-  - is_true: "elastic/enterprise-search-server"
   - is_true: "elastic/fleet-server"
   - is_true: "elastic/fleet-server-remote"
   - is_true: "elastic/kibana"