py3: keep stdout as defined by pycompat in procutil
According to https://docs.python.org/3/library/functions.html#open, it's
not possible to use 1 as buffering argument value in binary mode. This
is probably why line buffering does not work well in python3.
On the other hand, sys.stdout.buffer appears to be line-buffered already
on python3. So by not replacing it, there should be no behavior change.
This fixes buffering issue in "hg email" (confirmation prompt shown
before information to be confirmed).
[tool.black]
line-length = 80
exclude = 'build/|wheelhouse/|dist/|packages/|\.hg/|\.mypy_cache/|\.venv/|mercurial/thirdparty/|hgext/fsmonitor/pywatchman/|contrib/python-zstandard/'