Update dependencies

[lindsay-stevens]

• Update from python 3.8 to 3.12
• Update dependencies: requests, toml, pydantic, + docs deps
• Update pyodk config to match pyxform e.g. pyproject.toml, updated GitHub actions, etc
• Apply linter suggestions from ruff

What has been done to verify that this works as intended?

Ran linter, test suite, and compiled / browsed docs site locally.

Why is this the best possible solution? Were any other approaches considered?

The project layout updates went well for pyxform so to avoid 2 different styles it was copied over to pyodk. I considered older versions of Python than 3.12 but it's been out for 5 months now with 2 patch releases so probably stable enough. It seems to work with all the dependencies.

How does this change affect users? Describe intentional changes to behavior and behavior that could have accidentally been affected by code changes. In other words, what are the regression risks?

Users will need to upgrade python versions.

Do we need any specific form for testing your changes? If so, please attach one.

N/A

Does this change require updates to documentation? If so, please file an issue here and include the link below.

The readme and PR template have been updated accordingly.

Before submitting this PR, please make sure you have:

• included test cases for core behavior and edge cases in tests
• run python -m unittest and verified all tests pass
• run ruff format pyxform tests and ruff check pyxform tests to lint code
• verified that any code or assets from external sources are properly credited in comments