Fix build artifact uploads

[webbnh]

Changes introduced with this PR

As of v4 of actions/upload-artifact, "it is no longer possible to upload to the same named Artifact multiple times." However, the current build runs repeatedly, for each of Python 3.9, 3.10, and pypy3.9, each of which uploads a number of artifacts, most of which have the same name in each run. So, on the second run, the attempt to upload the coverage HTML artifact now fails, or, at least, it did in #122 (it is possible that the problem is timing-related -- it did not happen in #120 or #119).

This change extends the changes in #120 to the other pushed artifacts, so that they have unique names suffixed with the version of Python used in the run.

This change also relaxes the version of Poetry used from 1.4.2 to any 1.4.

---

By contributing to this repository, I agree to the contribution guidelines.

[dbutenhof]

Well, it looks plausible!

[jaredoconnell]

Seems fine. I wonder if Poetry cares about that version at all. Probably not because it's in a run block.

[webbnh]

I wonder if Poetry cares about that version at all. Probably not because it's in a run block.

This is the installation of Poetry...so, it doesn't get to think about this -- rather, this controls what Poetry gets to think! 🙃