Fix lint dependencies for Python 3.14

[brianbeck-google]

Repro:

• Change 3.13 to 3.14 in .github/workflows/build.yml
• cd software && make lint

Error:

cd software && make lint
if [ -d ".venv" ]; then . .venv/bin/activate; fi
python -m isort --diff authbox *.py
python -m black --check authbox *.py
python -m flake8 authbox *.py
All done! ✨ 🍰 ✨
29 files would be left unchanged.
authbox/badgereader_wiegand_gpio.py: "pyflakes[F]" failed during execution due to AttributeError("module 'ast' has no attribute 'Str'")
Run flake8 with greater verbosity to see more details
make: *** [Makefile:44: lint] Error 1
Error: Process completed with exit code 2.

ast.Str was removed in Python 3.14 but something is still using it. Probably need to update a dependency