Remove now unused compat symlinks

The new names have now been in use for a while so drop the compat
symlinks.

See: https://pagure.io/pungi-fedora/pull-request/1292
See: https://pagure.io/fedora-infra/ansible/pull-request/2372

Kinoite: Set variant to 'kinoite' by default

The variable is overridden as needed in Kinoite Mobile manifests.

This does not introduce any change to the final processed manifests.

common: Default to Bootable Containers, override as needed

Default to building Bootable Containers and override as needed for the
classic ostree manifests.

This does not introduce any change to the final processed manifests.

XFCE & LXQt still require Perl