Switch to gitlab auth for openqa.gnome.org
It turns out that using GNOME LDAP accounts for openqa.gnome.org is too limiting. During Outreachy the interns don't have access to the web UI for openqa.gnome.org and its not clear how we could get them LDAP accounts under the New Accounts policy. We should switch to using Gitlab auth so that anyone with a Gitlab account can modify the tests.