Sync typeshed (#21707)

Source commit:

python/typeshed@f76037a

Author: github-actions[bot]

mypy/typeshed/stdlib/builtins.pyi

@@ -1277,7 +1277,6 @@ if sys.version_info >= (3, 15):
             cls: type[frozendict[str, _VT]], iterable: Iterable[tuple[str, _VT]], /, **kwargs: _VT
         ) -> frozendict[str, _VT]: ...
 
-        def __init__(self) -> None: ...
         def copy(self) -> frozendict[_KT, _VT]: ...
 
         @overload