typing: add explicit hints for recent pytype regressions
Somewhere between
454feddab720 and
cd72a88c5599, pytype changed how it inferred
the return type in `extdiff.py` from
Tuple[Any, List[Tuple[bytes, Any, os.stat_result]]]
to
Tuple[Any, List[nothing]]
It also changed the return type in `archival.py` from `Any` to `NoReturn`. Fix
those up, and also the obvious parameter types while we're here.
[workspace]
members = ["hg-core", "hg-cpython", "rhg"]
exclude = ["chg", "hgcli"]
resolver = "2"