Extend the CI build support, including testing the soup backend
Extend the CI build support, including testing the soup backend

This adds a separate, more modern CI build running on ubuntu 22.04
using curl, and leaves the old one around building against soup.

In addition, the modern one uses the system bwrap and dbus-proxy so
that we test these configurations too (and because the modern system
has good versions of these).

I also enabled running parallel make check again, hoping that
whatever made this hang is now fixed. We'll see.

flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak