windows: prevent bytes from being passed to registry APIs
There was a TortoiseHg bug report in this area[1], and from inspection, it looks
like passing `b""` as `valname` would fail to convert to unicode. The
underlying API allows both `""` and `NULL` to return the default value for the
key.
[1] https://foss.heptapod.net/mercurial/tortoisehg/thg/-/issues/5803
[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