tests: conditionalize the progress timestamp for Windows
It looks like for py2 on Windows, the start date is 1970. It matches the other
platforms for py3, so I'm just going to match the tests and move on, given that
py2 is on the way out.
Differential Revision: https://phab.mercurial-scm.org/D9541
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true