Revert "gitlab-ci: disable panfrost runners"

Revert "gitlab-ci: disable panfrost runners"

The infrastructure issues, caused by building electrical works gone
wrong, have been fixed, and the Panfrost LAVA runners are available
again.

This reverts commit a86662c44d7cb2541c3f613805533064219ad11f.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4019>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4019>