Migrate the wiki to keycloak
In the future we want to use keycloak for authentication mediawiki:
- https://www.mediawiki.org/wiki/Extension:OpenID_Connect
- https://stackoverflow.com/questions/16893589/prevent-users-from-changing-their-passwords-in-mediawiki
- https://wiki.archlinux.org/index.php/ArchWiki:Access_levels_and_roles
/cc @pierre @archlinux/teams/wiki/admins