Switch project to use pyproject.toml

[hagenw]

This modernizes the Python infrastructure of the project:

• Replace setup.py and setup.cfg by pyproject.toml
• Replace PEP8 checking in pre-commit with flake8 by ruff
• Add checking for common spelling errors with codespell in pre-commit

[codecov[bot]]

Codecov Report

Merging #56 (0e6cd88) into main (dc32460) will not change coverage. The diff coverage is 100.0%.

Files Changed	Coverage Δ
audfactory/core/lookup.py	100.0% <ø> (ø)
audfactory/__init__.py	100.0% <100.0%> (ø)
audfactory/core/api.py	100.0% <100.0%> (ø)