urlutil: make `paths` class old list of `path`
We move from a `{name → path}` mapping to a `{name → [path]}` mapping. And
update all user code accordingly. For now, all the list contains exactly one
element, but we are now in a good place to make the config understand a list of
url.
Differential Revision: https://phab.mercurial-scm.org/D10447
[build-system]
requires = ["setuptools", "wheel"]
build-backend = "setuptools.build_meta"
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true