Add pyright support

[szvsw]

PR Checklist

• A description of the changes is added to the description of this PR.
• If there is a related issue, make sure it is linked to this PR.
• If you've fixed a bug or added code that should be tested, add tests!
• Documentation in docs is updated

Description of changes

This enables user-selection of the typechecking engine, using mypy and pyright as the available options. The main changes are to:

1. Install the appropriate dependency.
2. Update the relevant pyproject.toml section
3. Update the makefile to run the appropriate test.
4. Update the GH action to run the appropriate test
5. Update the tox to run the appropriate test NB: I am not a tox user so I haven't tested this part out yet, but it seems like it should be fine!

I have not yet added tests as I'm curious what you think the correct approach should be for the typechecking tests.

Closes #106

[fpgmaas]

Thanks for your contribution!