Make sure that the host is using llvmpipe while the guest is using virgl as driver.
Note that the neverball/neverball.trace trace actually regressed in a way that the
foreground is missing.
Fixes: f1b952fa ("ci: Run tests inside Crosvm")
Signed-off-by: Corentin Noël <corentin.noel@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11986>