We can now reference reusable workflows with local syntax

[briantist]

What does this mean?

It means we have a way to run tests against changes to shared workflows, by referencing them as "local":
https://github.blog/changelog/2022-01-25-github-actions-reusable-workflows-can-be-referenced-locally/

Basically, just like we do for the actions, we can create workflows in the repo that reference the shared workflows, to run tests against PRs and pushes to the workflows.

What this does not mean

This doesn't solve #4 , because there is still no way to load an action locally from the same repo as a shared workflow, as far as I can tell.