Switch our Jenkins ISO build system to vagrant-libvirt

Being able to have reproducible builds asks to use the same build system everywhere. We should update our isobuilders and manifests to switch the ISO build process on Jenkins to the now canonical way of using vagrant-libvirt.

Feature Branch: wip/11972-use-vagrant-in-jenkins

Parent Task: #5630 (closed)

Subtasks

#12017 (closed)
#12327 (closed)

Related issues

Related to #12009 (closed)
Related to #12503
Blocks #11979 (closed)
Blocks #11980 (closed)

Original created by @bertagaz on 11972 (Redmine)

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