Fix version tests in CI

[gmgunter]

Fix version tests in CI by fetching tags when checking out the repo so that setuptools_scm correctly infers the version syntax.

[gmgunter]

One of the unit tests checks the format of the __version_tuple__ attribute generated by setuptools_scm. By default, setuptools_scm doesn't include a patch version number -- only major & minor numbers. In order to add the patch number, it needs to see an existing tag that has one.

The unit test ensures that the patch number is present. It was failing in CI since the default behavior of actions/checkout is to fetch only the HEAD of the branch, excluding the version history and tags (see actions/checkout#249).

actions/checkout#579 is supposed to be a fix for this, but AFAICT it does not actually cause tags to be fetched. Ultimately, the fix that I ended up with was fetching the full history + tags. This seems to resolve the issue, and I don't imagine the history ever getting large enough that it presents a meaningful bottleneck for testing.