Packit as a CI for Fedora dist-git pull requests

[lachmanfrantisek]

Since Fedora-CI is being deprecated and Zuul is being transferred to the Testing Farm for the limited time for maintenance, Packit can take this role and help Fedora there.

Why?

• Our users ask us quite regularly to have the same UX upstream/downstream and to have full workflow covered by PAckit.
• We already have most of the code/integration/events ready nevertheless.
• We are currently working on Research Packit reverse-dependency checks #2361 and as part of that, support for dist-git PRs would be needed nevertheless.
• It looks to me like there is not much will/time to maintain Fedora-CI/Zuul-based solution so would be nice of us to help here. Without proper CI, Packit-proposed pull-requests do not make much sense.

Thinks to consider/discuss/think about:

• Have it as part of the current instance? Or a separate instance?
• What about configs? Should we add support for global config or even (really not sure about this) run automatically for all the packages? (Might be more a political discussion than a technical one..;)
• Should we move to the Fedora OpenShift?

Tasks:

• Research Packit as a Fedora dist-git CI #2462