Separate vkd3d distribution

[Bleuzen]

Hi, currently there is always a new release for lutris for both (dxvk and vkd3d) when there is a new dxvk release.
However, since dxvk is pretty much complete, it doesn't see frequent releases anymore.
With vkd3d under very active development, it would nice to update it more often.
So it could be a good idea to publish updates to vkd3d even if there is no new dxvk release.
Maybe these two should be separated from now on, what do you think?

[Bleuzen]

@tannisroot

[strycore]

Aside from saving a few megabytes in the downloads, I don't see the big advantage doing this. Even if it's under heavy development, we don't update VKD3D if there isn't a reason to do so.
If we had a nightly build channel, it would make sense but at the moment we only have a "stable" release channel.