typing: make the manifest classes known to pytype
These are the same changes as
c1d7ac70980b and
45270e286bdc made to dirstate,
for the same reasons. The migration away from decorating the classes with
`@interfaceutil.implementer` was started back in
3e9a660b074a, but missed one.
[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