hghave: update expected rustfmt version We still use nightly, but have moved to a newer nightly after the last CI image upgrade in 74f1bf147a6d and 3876d4c6c79e.

rustfmt: apply formatting expected by newer nightly version This was missed in 3876d4c6c79ec5c71e8c51b876cc157e93a5eaac somehow.

tests: stop skipping `mercurial/pure/osutil.py` during pytype runs Not sure when the original issue(s) were fixed, but it works for me now.

largefiles: avoid a potentially undefined variable in exception case The `wlock` variable is used to release the lock in the `finally` block, so it would be undefined if `repo.wlock()` itself failed. Caught by pytype 2024.04.11 with py3.10.11.

typing: add trivial type hints to `mercurial.scmutil` There's still a lot to go, but there's a lot here already, so I tried to keep it to obvious/trivial things. I didn't bother with contexts, matchers, and revisions that can be `bytes | int | None`.

typing: narrow the scope of some recent disabled import warnings These comments were added in 39e2b2d062c1, but had the effect of changing the known type to `Any`, which cascaded through a few function signatures. Just ignore the import error instead.