Remove Vulkan SDK from OCK

[coldav]

Vulkan SDK is built by default on OCK. This leads to

• bloated code
• maintenance overhead (including requirements on compiler_pipeline)
• requires users to download vulkan sdk unless they limit to "cl" causing confusion.
• slows testing down (including installation time and running tests - a few minutes each run).

On top of this it is not a full vulkan implementation and has little relevance to it's usage within oneAPI/UXL.

I'd like to move to a full RFC for this.

[hvdijk]

It makes sense to me to get rid of things that we have no use for. Do we know if anyone may be using it?

[coldav]

I've not heard of anyone using it, it was created for a project a long time ago.