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]

Codecov Report

Merging #383 (fb1c906) into main (d20e70f) will not change coverage.
The diff coverage is 100.0%.

Impacted Files	Coverage Δ
audformat/core/typing.py	100.0% <ø> (ø)
audformat/__init__.py	100.0% <100.0%> (ø)
audformat/core/attachment.py	100.0% <100.0%> (ø)
audformat/core/column.py	100.0% <100.0%> (ø)
audformat/core/common.py	100.0% <100.0%> (ø)
audformat/core/database.py	100.0% <100.0%> (ø)
audformat/core/index.py	100.0% <100.0%> (ø)
audformat/core/scheme.py	100.0% <100.0%> (ø)
audformat/core/table.py	100.0% <100.0%> (ø)
audformat/core/testing.py	100.0% <100.0%> (ø)
... and 5 more