branchcache: rework the `filteredhash` logic to be more generic
We now have a more flexible `key_hashes` tuple. We duplicated various logic in
the V2 and V3 version of the cache as the goal is to start changing the logic
for V3 in the next few changesets.
[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