ci/freedreno: Switch the piglit testing to the new piglit runner.

ci/freedreno: Switch the piglit testing to the new piglit runner.

Getting piglit to fit onto our test devices was proving difficult, and we
need the ability to handle flakes, so switch to the rust piglit runner
that @pepp wrote as part of the deqp-runner repo which gives us flake
detection, sharding across boards, fractional runs, and almost half the
runtime.

It doesn't handle piglit subtests yet, but if you can't run piglit's
python on your devices because it's too bloated and unstable, this is a
way forward.

Reviewed-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9468>