Removal of Vagrant LXC boxes for Buster und subsequent releases

[Emmanuel Kasper <emmanuel@libera.cc>]

Hi
Due to lack of maintainer time, and as Debian Vagrant LXC boxes are
currently broken, I am going to remove the boxes from the Vagrant Cloud
Repository.
If someone have an interest on working on Vagrant LXC boxes, the code to
generate the boxes is in
https://salsa.debian.org/cloud-team/vagrant-boxes and I am happy to
support uploading.
Emmanuel

-- 
You know an upstream is nice when they even accept m68k patches.
  - John Paul Adrian Glaubitz, Debian OpenJDK maintainer