transaction: do not rely on a global variable to post_finalize file
We can just add a new argument to the `addfilegenerator` function. This is more
explicit and therefor clearer and less error prone.
Differential Revision: https://phab.mercurial-scm.org/D12125
[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