Add security-testing repo to nightly runs

[deeplow]

Add security-testing to nightly test runs. Ping @legoktm

(not sure if this is the right repo, feel free to transfer the issue)

[legoktm]

Thanks for filing and yes, correct repo. The goal here is to run our CI with proposed security fixes to help with catching any possible regressions.

https://www.qubes-os.org/doc/how-to-install-software-in-dom0/#testing-repositories is the documentation I found on how to enable security-testing.

To enable or disable any of these repos permanently, change the corresponding enabled value to 1 in /etc/yum.repos.d/qubes-dom0.repo.

So I think we'd want:

• When the VM boots up, we enable the repository permanently
• run sudo qubes-dom0-update -y to pull in any pending changes
• Reboot the VM
• Then we kick off our provisioning and test run.
• When we send the notification back to Slack, it should clearly indicate that this was a variant with security-testing enabled.

I think this mimics what a real world experience would be.

Only problem is that we don't yet have the ability to reboot, but we need/want that for other things, so maybe we should just do it.