Add TypeVars for the Iterators in select.select (#15022)

Author: marsfan

stdlib/select.pyi

@@ -2,8 +2,8 @@ import sys
 from _typeshed import FileDescriptorLike
 from collections.abc import Iterable
 from types import TracebackType
-from typing import Any, ClassVar, Final, final
-from typing_extensions import Self
+from typing import Any, ClassVar, Final, TypeVar, final
+from typing_extensions import Never, Self
 
 if sys.platform != "win32":
     PIPE_BUF: Final[int]
@@ -31,9 +31,13 @@ if sys.platform != "win32":
         def unregister(self, fd: FileDescriptorLike, /) -> None: ...
         def poll(self, timeout: float | None = None, /) -> list[tuple[int, int]]: ...
 
+_R = TypeVar("_R", default=Never)
+_W = TypeVar("_W", default=Never)
+_X = TypeVar("_X", default=Never)
+
 def select(
-    rlist: Iterable[Any], wlist: Iterable[Any], xlist: Iterable[Any], timeout: float | None = None, /
-) -> tuple[list[Any], list[Any], list[Any]]: ...
+    rlist: Iterable[_R], wlist: Iterable[_W], xlist: Iterable[_X], timeout: float | None = None, /
+) -> tuple[list[_R], list[_W], list[_X]]: ...
 
 error = OSError