Add support for nvcc-specific matrix.

[jrhemstad]

Description

closes #240

Adds a nvcc: field under the pull-request field of matrix.yaml in preperation for adding other nested fields for other kinds of jobs under pull-request.

Updates the compute-matrix job to use a compute-matrix.sh script to make it easier to test locally. Also updated the job itself to extract an nvcc-specific matrix.

• Add nvcc field to matrix.yaml
• Refactor compute-matrix logic into bash script
• Refactor compute-matrix workflow into composite action
• Update compute-matrix job to invoke compute-matrix composite action
• Update compute-matrix job to compute the NVCC specific matrix attributes like PER_CUDA_COMPILER as further post-processing after invoking the composite action

Checklist

• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[gevtushenko]

I can see that compute-matrix action works fine, but I'm unable to find where PER_CUDA_COMPILER_MATRIX, CUDA_VERSIONS etc. are in it's output.

[jrhemstad]

I can see that compute-matrix action works fine, but I'm unable to find where PER_CUDA_COMPILER_MATRIX, CUDA_VERSIONS etc. are in it's output.

Yeah, it's still in progress 🙂. I forgot to open the PR as a draft and so it assigned reviewers. When I converted it back to a draft, it didn't clear the reviewers.

You can hold off on reviewing until I convert it back to ready for review.