ci: remove py2-rust support
Nobody cares about this very narrow usecase, and py2 support is over by
July 1st. This helps with the CI load, and removes some flakiness.
[build-system]
requires = ["setuptools", "wheel"]
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true