branchcache: allow to detect "pure topological case" for branchmap
We don't rum this detection every time we run the branchcache, that would be
costly. However we now do it when running `hg debugupdatecache`.
This will help existing repository to benefit from the fastpath when possible.
[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