Don't use ci/action-build-package@master in actions.yml anylonger, spell its steps out one-by-one in reusable.yaml instead. This makes the step names appear as log section headers in the UI, which is more explicit and, hence, nicer.
This pretty much obsoletes the composite actions.yml. It should be probably removed, and since this changes the point of this repository from providing an action to providing a workflow, it shoud probably be renamed from action-build-package to workflow-build-package or something.
Signed-off-by: Jan Lindemann <jan@janware.com>