CI: some improvements to switch some jobs to v2.x
Some of the jobs could use (and benefit from using) v2.0 images, and some probably v2.1 images which have pyenv and a set of different python versions.
All legacy (hg-git based) Projects have been automatically migrated to native with the upgrade of 2025-01-23
Some of the jobs could use (and benefit from using) v2.0 images, and some probably v2.1 images which have pyenv and a set of different python versions.