For embargoed releases it is useful to apply patches locally to build
with them before they are public. This allows to push the same patches
to the repo during the Flatcar release at the embargo lift. The result
is the same (as long as the scripts patches did not change parts of the
setup logic that was running before they got applied), we can just build
earlier and thus do the Flatcar release directly on the embargo lift
instead of having to wait with the build because it would require the
patches to be in the repos.
Currently we skip the nightly build if there are no changes. This
didn't work well because a new run doesn't fix any failure because the
rerun became a no-op.
Check if the main artifacts we expect from a step are found, as simple
heuristic on whether a rerun is needed.
When the build system runs the packages jobs for both architectures in
parallel and has to create a new tag, tagging fails due to the race in
the tagging.
Move the git tagging to its own script that is run from a new top-level
job that starts the packages jobs for both architectures.
