Add Reusable Workflow?

[mdavidsaver]

At some point github actions added the ability for one repository to use a workflow defined in another. (via. a short "stub" workflow in the calling repository)

https://docs.github.com/en/actions/using-workflows/reusing-workflows

In seems worth exploring if this could be leveraged to eg. avoid maintaining copies of large job matrices into every module using ci-scripts.

[ralphlange]

Good idea.

Still: I think every single application of ci-scripts that I maintain uses a different matrix.