OAuth login for the Authentiq provider is not tested with a feature spec

!11963 (merged) added feature specs for all OAuth-based login providers, including Authentiq.
Autoloads for the Authentiq module were causing the migration:path builds on master to fail, so !11963 (merged) was reverted.
This was fixed (https://gitlab.com/gitlab-org/gitlab-ce/issues/34713 / https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12668) by removing the Authentiq provider from this test.
We need to figure out a way to test the Authentiq provider in oauth_login_spec.rb without having the migration:path-pg build failing.