kolaTestIso: add miniso-install to UEFI scenarios

[jlebon]

This is tested on BIOS already, but it's useful to test on UEFI too because it implicitly also verifies that we can change kargs in the UEFI grub.cfg.

[dustymabe]

This LGTM, but let's hold it until this week's releases are out.

One other thing here. With the new pipeline work/migration these tests are quickly becoming "global", which means they need to run on older RHCOS releases (even ones that didn't have miniso support). I think we're going to need to accelerate denylist support for testiso bits (even if it's a hacky short term solution).

[cgwalters]

With the new pipeline work/migration these tests are quickly becoming "global", which means they need to run on older RHCOS releases

Short term, I think we can explicitly only target building oscontainers for older RHCOS releases and backfill disk images. That is way, way, way more important than disk images.

(This also of course goes into coreos/coreos-assembler#2685 which creates a clearer distinction between these two things)

[jlebon]

This was fixed a better way via coreos/coreos-assembler#3298.