Drop support for Debian 9 (Stretch)
LTS version of Debian 9 reaches EOL on 2022-06-30.
Proposal:
-
drop it from .gitlab-ci.yaml on all supported branches -
stop bothering ourselves with libraries and Python versions used by Debian 9 -
drop it from list of Regularly Tested Platforms in the ARM -
update KB article
Edited by Michał Kępień