Make multiple improvements to the existing workflows:
- create a shared custom action to deal with version number tracking
and generation;
- use this action to add the branch name to the version for pull
request builds;
- create a shared workflow for all debian-ish builds to avoid re-use
by copy / paste;
- remove potential security risks by eliminating the use of
pre-evaluated expressions (`${{ ... }}`) inside scripts;
- update outdated GitHub action versions;
- improve the consistency by renaming scripts acording to have a `.sh`
extension;
- improve naming of generated artefacts for pull requests to include
the correct version.
@dirkh: Unfortunately this is potentially going to break builds when it is
merged, as there is no good way to 'test' a merge build short of
merging.
We'll just have to deal with the fallout of it in a follow-up pull
request.
Signed-off-by: Michael Keller <github@ike.ch>
