xwayland: Add and hook up test script
The main purpose of this MR is the last commit, pretty straightforward.
However, running the new test script in CI requires installing weston
in the docker image, which led me down a little rabbit hole, ending in two fixes for the image build with current Debian testing.
Also, while we're at it, update to the latest ci-templates
, and take advantage of $FDO_CI_CONCURRENT
.
/cc @ofourdan