Improve customizability for downstream projects
The osname ("apertis" in our case) is used mainly in three places:
- the packaging branch prefix like
apertis/v2020
- the packaging tag prefix, like
apertis/1.42
- the OBS project for the upload, like
apertis:v2020:target
This MR is meant to address 2, while point 3 was addressed by commit 1d04a67d.
This MR also partially addresses point 1,with the final fix blocked by the upstream issue https://gitlab.com/gitlab-org/gitlab/-/issues/35438.
Edited by Emanuele Aina