ci: Support per-driver skip lists.

ci: Support per-driver skip lists.

In addition to a global skip list introduced in
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11333
(enabled by
https://gitlab.freedesktop.org/anholt/deqp-runner/-/merge_requests/4)
it is also useful to have a per-driver skip list in addition to a
per-gpu list. Now, there are multiple levels at which skips can be
specified, from least to most specific,

  - (deqp|piglit)-all-skips.txt :: affecting all tests
  - (deqp|piglit)-$(DRIVER_NAME|VK_DRIVER|GALLIUM_DRIVER)-skips.txt ::
  affecting the specified driver
  - (deqp|piglit)-$GPU_VERSION-skips.txt :: affecting a specific GPU

This idea could be useful for -fails.txt as well.

Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Martin Peres <martin.peres@mupuf.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11426>