typing: make minor adjustments to mercurial/util.py to pass pytype checking I'm assuming the wrong-arg-count is a pytype bug, because this code is used by the config object. Avoiding initializing `_lrucachenode` node points to None eliminates a few `is not None` assertions, but apparently not all of them. I can't figure out why it gets confused over the state where these new assertions are. Differential Revision: https://phab.mercurial-scm.org/D10276

[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