The original intention of the "binpkg" prefix in the CI binary package
cache URL was to separate packages from other build artifacts like
containers, images, and SDK tarballs. Motivation was to separate
developer content (binary packages) from CI automation artifacts
(everything else); since binary packages are not used by the CI.
This broke assumptions in scripts which use the binary host URL for
other things than packages - e.g. SDK tarballs or images. These
scripts would get a bincache URL with "binpkg/" prepended, while CI
automation would *not* use that prefix.
This change removes the use of "binpkg/" altogether since it would not
work as intended without more significant changes to build scripts.
This change adds a job for publishing binary packages to the build cache
server to the ci automation.
Also, setup_board is updated to use the buildcache package cache if a
nightly build version is detected.
Signed-off-by: flatcar-ci <infra+ci@flatcar-linux.org>
