tails::website requires rssh, which is not in Debian Buster and newer
A year ago, puppet-tails@f314441d installed rssh. Unfortunately, rssh had already been removed from recent Debian at that point because "orphaned upstream, flawed security model", so this class cannot be deployed on clean systems. The only reason this does not break our current deployment on www.lizard is that we still have an old version of rssh installed.
Tentatively assigning to groente who added this.