The new 'build-images' job rebuilds ceph-csi:canary, ceph-csi:devel and
ceph-csi:test images after a PR has been merged in the master branch.
These images can then be used by other CI jobs, to improve the speed by
reducing unneeded rebuilds of the images.
Signed-off-by: Niels de Vos <ndevos@redhat.com>
