Research: Use GHA to drive GCP-backed beaker tests

[op-ct]

[op-ct]

we have a matrix of GHA-only beaker tests running in GCP.
The matrix data is loaded from repo-bound JSON file, which is a.) data-only and b.) now the only unique CI content in the repo: https://github.com/op-ct/pupmod-simp-aide/actions/runs/5050852240

There are still some things to do to pretty this up and probably a whopper of a conversion script to get the acceptance/compliance tests out of .gitlab-ci.yml

But if this paradigm works well, we can get off of gitlab.com CI entirely

A tempting next step would be to move all common GHA workflow content into a versioned repo & switch the component repos to shim workflows that simply point to their associated One True Workflow at the major version (branch) to use (@v1, @v2, etc

HOWEVER:

The SSH connections from github to GCP-hosted beaker instances keep failing on ssh IOerrors:

I'm not sure what the best solution to this is yet. More than likely it's something on the gituhub actions enviornment's side. If we can't fix that, probably the next best move is spinning up or self-hosted github action runners.