Support Pydantic <1.11, Test compatibility among supported Python and pydantic versions.

[ewdurbin]

Closes #119

This is just a draft of setting up an initial test matrix

Code Changes

• Loosens dependency spec for pydantic
• Updates pytest for 3.10+ compat
• Builds a simple noxfile.py
• add matrixes for static checks and tests

Steps to Confirm

• run nox locally
• look at GitHub actions results

Pre-Merge Checklist

• All CI Pipelines Succeeded
• Documentation Updated
• Issue Requirements are Met
• Relevant Follow-Up Issues Created
• Update CHANGELOG.md

Description Of Changes

In order to be generally usable as a library, fideslang should do its best to test against varying Python versions and versions of libraries it depends on. Given that pydantic compatibility is relatively sensitive, this is the only library targeted in this effort.

[ewdurbin]

@ThomasLaPiana, here's an initial sketch of a nox based test matrix for fideslang.

Major downside here is that the lack of nox integration means enumerating our matrix in two places (noxfile.py and the GitHub workflow). I'm going to look into if there's a well supported way of automatically discovering them.

[ThomasLaPiana]

Thank you so much for this!