This will also make the unneeded "VCS Password" personal settings panel at https://phabricator.wikimedia.org/settings/panel/vcspassword/ disappear, and ideally (I did not check though) create two clone URIs less whenever we create a new mirrored repository in Diffusion.
TODO:
- Disable in the UI via https://phabricator.wikimedia.org/config/edit/diffusion.allow-http-auth/
- Remove from default settings via patch in GitLab: "diffusion.allow-http-auth" in https://gitlab.wikimedia.org/repos/phabricator/deployment/-/blob/wmf/stable/scap/templates/phabricator/conf/local/local.json.j2