ci: Merged workflows via ubuntu os matrix

[M2-TE]

You mentioned wanting to incorporate cuda/optix workflows soon, so I wanted to potentially make your life a little easier by merging some of the workflow files.

With the strategy key in GitHub actions, you can provide an array and it will launch a runner for every entry.

I've not done this, but with another array such as [core, embree, cuda, optix], it could launch a runner for every combination while only needing a single workflow file (when the code they have to execute differs too greatly, it might make sense to separate them as they are now)

...if it works as expected

[amock]

Yes, the matrix functionality is very helpful. I was actually planning to integrate it, so thanks for being quicker! :) However, the bigger issue was that GitHub didn’t have any CUDA runners at the time I was writing the tests. Additionally, I didn’t have a good solution for running workflows on private machines and keeping them online all the time.

[M2-TE]

To run workflows on private machines, you can probably make good use of something like act to run workflows in docker containers. They should even be CUDA-capable, but I haven't tested that myself.