packaging: delete unnecessary updating of `dirs` list The `dirs` list is not used and it seems it also wasn't used when this code was added in 395b0e132836 (Don't copy hidden files/directories during `setup.py install`, 2009-07-14). Differential Revision: https://phab.mercurial-scm.org/D8857

[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true