We don't need these Vulkan bits, so let's try not building them. This might seem kind of petty, but given that we build dEQP four times for GL (once for GL, once for GLES, once for EGL/X11, and once for EGL/Wayland), it does actually make a measurable difference to the time spent rebuilding dEQP. Signed-off-by: Daniel Stone <daniels@collabora.com> Reviewed-by: Eric Engestrom <None> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33287>