Extends the existing group variables API to support
EE-only params, and allows setting the environment_scope
if the :group_scoped_ci_variables licensed feature is available.

If the feature is not available (pricing tier is not Premium or
higher), the param is silently removed and the update continues
without presenting an error to the user. This behaviour is the
same as when project level scoped variables were a premium feature.

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/55573