Uses non-feature-gated GitLab team member check

Related to work of allowing GitLab-owned service_users to be
allowlisted.

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/45310
implemented this, but one of the checks for the service_user
belonging to GitLab was feature-gated.

ee/app/models/ee/user.rb

@@ -345,7 +345,7 @@ module EE
 
     def gitlab_service_user?
       strong_memoize(:gitlab_service_user) do
-        service_user? && ::Gitlab::Com.gitlab_com_group_member_id?(id)
+        service_user? && ::Gitlab::Com.gitlab_com_group_member?(id)
       end
     end