Build without GPU support

[Zahrun]

Hi there,

I tried to update obs-backgroundremoval in Nix several months ago in NixOS/nixpkgs#230775, but got stuck by the lack of onnxruntime-gpu in Nix NixOS/nixpkgs#228093.

As far as I understand, in Nix, they do not allow the loading of external dependency during build process apart from other nix packages (which forces USE_SYSTEM_ONNXRUNTIME).

There is an attempt to add onnxruntime-gpu in NixOS/nixpkgs#260745.

It seems that cuda and onnxruntime-gpu are pretty heavy to compile.

As an alternative, would it be possible to build obs-backgroundremoval without GPU support, with only CPU mode available, that would not require tensorrt_provider_factory.h to build?

[spikespaz]

I am also awaiting this change, looking forward to a simpler build process!

[umireon]

@Zahrun Can you try #524 ?

[Zahrun]

Wow, thank you for the very fast implementation @umireon. I will try it in some time.