Type and mark as final module-level dunders not meant to be overwritten in stdlib/ (#9709)

stdlib/_csv.pyi

@@ -1,9 +1,9 @@
 from _typeshed import SupportsWrite
 from collections.abc import Iterable, Iterator
 from typing import Any
-from typing_extensions import Literal, TypeAlias
+from typing_extensions import Final, Literal, TypeAlias
 
-__version__: str
+__version__: Final[str]
 
 QUOTE_ALL: Literal[1]
 QUOTE_MINIMAL: Literal[0]