Use TypeAlias where possible for type aliases (#7630)

stdlib/functools.pyi

@@ -2,7 +2,7 @@ import sys
 import types
 from _typeshed import Self, SupportsAllComparisons, SupportsItems
 from typing import Any, Callable, Generic, Hashable, Iterable, NamedTuple, Sequence, Sized, TypeVar, overload
-from typing_extensions import Literal, final
+from typing_extensions import Literal, TypeAlias, final
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -54,7 +54,7 @@ else:
         "singledispatch",
     ]
 
-_AnyCallable = Callable[..., Any]
+_AnyCallable: TypeAlias = Callable[..., Any]
 
 _T = TypeVar("_T")
 _S = TypeVar("_S")