CI: update images: fedora-40, opensuse-15.6, opensuse-tumbleweed [NEW]
- add openSUSE Leap 15.6 images
- use
python3.11 - update install and platform docs
- use
- add openSUSE Tumbleweed images and jobs
- add latest Fedora 40 images
- remove old
debian-{10,11}-fulltest images
Edited by Jakub Ružička