Update typing_extensions imports in third-party stubs (#11245)

stubs/dockerfile-parse/dockerfile_parse/parser.pyi

@@ -1,7 +1,6 @@
 import logging
 from collections.abc import Mapping, Sequence
-from typing import IO, ClassVar
-from typing_extensions import TypedDict
+from typing import IO, ClassVar, TypedDict
 
 from .util import Context
 

stubs/dockerfile-parse/dockerfile_parse/util.pyi

@@ -1,7 +1,7 @@
 from collections.abc import Generator, Mapping, MutableMapping
 from io import StringIO
-from typing import ClassVar
-from typing_extensions import Literal, TypeAlias
+from typing import ClassVar, Literal
+from typing_extensions import TypeAlias
 
 def b2u(string: bytes | str) -> str: ...
 def u2b(string: str | bytes) -> bytes: ...