Define a narrow test set of poetry dependencies and run CI testing in that context

[dylanhmorris]

This will catch dependency problems that can be obscured when running in a general dev context, see e.g. #336

[dylanhmorris]

@CDCgov/multisignal-epi-inference-devs for awareness

[sbidari]

To be sure, this would mean creating a dependency group in pyproject.toml for running tests in CI? @dylanhmorris

[dylanhmorris]

Yes. I would suggest splitting the dev dependency group into a docs group and a test group. I think that should cover all of what's currently in dev, but if not we can thinking about what the other group(s) should be called