shelve: trust caller of shelvedfile.opener() to check that the file exists
The only place we call `shelvedfile.opener()` is when we're about to
apply a bundle. The file should always exist. If it doesn't, the
`.hg/` directory is corrupt and we don't provide any guarantees about
supporting corrupt repos (besides, telling the user that the shelve
doesn't exist when `hg shelve --list` lists it is not very helpful).
Differential Revision: https://phab.mercurial-scm.org/D9698
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true