docs: Add dri-devel to the mailing lists and drop the DRI wiki link.

The DRI wiki is a wasteland at this point, let's just fold the one bit of
useful information in here.

Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5507>
1 file changed