checker.py: Remove unneeded cast() (#13984)

Author: AlexWaygood

mypy/checker.py

@@ -7,7 +7,6 @@
 from contextlib import contextmanager, nullcontext
 from typing import (
     AbstractSet,
-    Any,
     Callable,
     Dict,
     Generic,
@@ -3453,8 +3452,7 @@ def check_multi_assignment_from_union(
                 assert declared_type is not None
                 clean_items.append((type, declared_type))
 
-            # TODO: fix signature of zip() in typeshed.
-            types, declared_types = cast(Any, zip)(*clean_items)
+            types, declared_types = zip(*clean_items)
             self.binder.assign_type(
                 expr,
                 make_simplified_union(list(types)),