Summary:
Pull Request resolved: #186323
Removes # mypy: allow-untyped-defs from torch/__init__.py (and adds a matching pyrefly.toml sub-config) and reworks how the magic methods on SymInt, SymFloat, and SymBool are typed.
Previously each class carried a long hand-written list of placeholder stubs like def __add__(self, other) -> "SymInt": .......