CI: Install python2
CI: Install python2

This is needed for the tests

Closes: #1741
Approved by: alexlarsson

flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak