ci/valve: do not extract the install tarball on the runner

ci/valve: do not extract the install tarball on the runner

Until now, we have been extracing the install.tar image on the gitlab
runner before sharing it to the test machine through a MINIO bucket.

It turns out that hardlinks and symlinks do not get shared, so let's
just extract the tarball directly on the test machine to fix the issue.

Signed-off-by: Martin Roukala (né Peres) <martin.roukala@mupuf.org>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16968>