`vagrant up` fails to connect to VM via SSH

[Christian Henz]

On Focal, Vagrant cannot connect to a new VM I tried to create (using debian/bookworm64).

`vagrant up my-bookworm-vm` keeps repeating:

"Warning: Authentication failure. Retrying..."

`vagrant ssh my-bookworm-vm` however works!

The reason is that public-key authentication fails when Vagrant uses ruby-net-ssh internally (it works with /usr/bin/ssh, which `vagrant ssh` is just a wrapper for).

The affected versions are:

vagrant: 2.2.6+dfsg-2ubuntu3
ruby-net-ssh: 1:5.2.0-1

I installed ruby-net-ssh version 1:7.2.0-1 from Mantic, which fixed the issue.