RFE: Replace Ubuntu VM image build for Debian SID

[cevich]

Goal: Test non-Fedora Distro, bleeding-edge environment (ideally with apparmor) in podman CI (and/or elsewhere).

According to https://image-finder.debian.net/ and searching around elsewhere, there are no ready-made Debian SID images available in for any cloud. However, there is automation available for producing them.. This seems to require a debian environment to run.

One idea could be: Replace the current CentOS-based image-builder-image (VM and container) with Debian. A Debian-based image-builder-image should easily be able to produce both Fedora and Debian SID images in GCE.

Alternately, a parallel Debian-based image-builder-image could be used only for building & importing a SID image into GCE.

/cc @edsantiago

[cevich]

For context: building and importing the Fedora GCE images mainly requires Packer and QEMU, both which should run w/o issue on a Debian VM.