Autologin

Just a piece of random feedback but if we want to be more crun/runc/krun-like (I think we should by default), if we can edit a couple of files in the rootfs of the vm before we boot, we can make it autologin.

```
Automotive Stream Distribution 9
Kernel 5.14.0-447.400.el9iv.x86_64 on an x86_64

localhost login: root (automatic login)

Last login: Fri Jun 7 20:37:43 on ttyS0
[root@localhost ~]#
```

It's basically replace:

-o '-p -- \\u'

with:

-a root

in the correct systemd getty .service file.