Fedora Zuul CI: new jobs to run Koji scratch build on specific arches

[Fabien Boucher]

Hi,

I'd like to introduce a recent change to Fedora Zuul CI.

Some packagers raised the need to get CI feedback for builds on supported
architectures.

So we have defined in Zuul some jobs that can be configured to be triggered
at PR's creation and update.

rpm-scratch-build-aarch64
rpm-scratch-build-armhfp
rpm-scratch-build-i386
rpm-scratch-build-ppc64le
rpm-scratch-build-s390x

Those new jobs have been configured to be triggered for Python3.x
repositories.
An example of PR that have triggered these jobs: [1]

See the wiki for more details: [2]

[1]:
https://src.fedoraproject.org/rpms/python3.9/pull-request/30#comment-63513
[2]: https://fedoraproject.org/wiki/Zuul-based-ci#Supported_build_arch