[Debian-salsa-ci] Proof of Concept about refactoring shell scripts into separate files out from yaml

[Ahmed Siam]

Hi!

I have recently finished this PoC where I separated the script of extract-source
job from salsa-ci.yml file into bash script files.

PoC MR: https://salsa.debian.org/salsa-ci-team/pipeline/-/merge_requests/528#note_511137

I intend to do the same for the rest of the jobs.

The purpose is to achieve goals mentioned here:
https://salsa.debian.org/salsa-ci-team/pipeline/-/issues/230

Let me know if you have any suggestions regarding the PoC.

-- Ahmed