ci: Move Vulkan CTS patches to their own directory

ci: Move Vulkan CTS patches to their own directory

VulkanCTS can receive patches from a reference to an upstream commit or by a
file stored in Mesa. Those locally stored patches for VulkanCTS should be
stored in the specific directory for patches with a prefix like skqp does.

The schema of how both sources apply patches has received a slight
modification to resemble each other.

Signed-off-by: Sergi Blanch Torne <sergi.blanch.torne@collabora.com>
Reviewed-by: Eric Engestrom <eric@igalia.com>
Acked-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22463>