Leverage CoreOS test framework for our CI

Talking to @cgwalters about issues with tmt for testing soft-reboots he suggested to leverage CoreOS's kola tests which we added soft-reboot support for in https://github.com/coreos/coreos-assembler/pull/4119

This probably can be achived with a github action that does something like:

1)
```
FROM quay.io/fedora/fedora-coreos:testing-devel
RUN layer new bootc
```
2) Create disk image

3) cosa kola run --output-dir /tmp/kolaself -E github/coreos/coreos-assembler/tests/kola-ci-self/ 'ext.kola-ci-self.autopkgtest-soft-reboot' --build=fedora-coreos-43.20250320.91.0-qemu.x86_64.qcow2.xz