update constructor args of the CFuncPtr to expand acceptable types (#10155)

* allow the second element of `_PF` to be `None`

* allow `__paramflags` to be `None`

* allow `__iid` to be `None` or `_CData`

* remove unused symbols

stdlib/_ctypes.pyi

@@ -2,7 +2,7 @@ import sys
 from _typeshed import ReadableBuffer, WriteableBuffer
 from abc import abstractmethod
 from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
-from ctypes import CDLL, c_int
+from ctypes import CDLL
 from typing import Any, ClassVar, Generic, TypeVar, overload
 from typing_extensions import Self, TypeAlias
 
@@ -94,7 +94,7 @@ class _CArgObject: ...
 def byref(obj: _CData, offset: int = ...) -> _CArgObject: ...
 
 _ECT: TypeAlias = Callable[[type[_CData] | None, CFuncPtr, tuple[_CData, ...]], _CData]
-_PF: TypeAlias = tuple[int] | tuple[int, str] | tuple[int, str, Any]
+_PF: TypeAlias = tuple[int] | tuple[int, str | None] | tuple[int, str | None, Any]
 
 class CFuncPtr(_PointerLike, _CData):
     restype: type[_CData] | Callable[[int], Any] | None
@@ -108,11 +108,11 @@ class CFuncPtr(_PointerLike, _CData):
     @overload
     def __init__(self, __callable: Callable[..., Any]) -> None: ...
     @overload
-    def __init__(self, __func_spec: tuple[str | int, CDLL], __paramflags: tuple[_PF, ...] = ...) -> None: ...
+    def __init__(self, __func_spec: tuple[str | int, CDLL], __paramflags: tuple[_PF, ...] | None = ...) -> None: ...
     if sys.platform == "win32":
         @overload
         def __init__(
-            self, __vtbl_index: int, __name: str, __paramflags: tuple[_PF, ...] = ..., __iid: _Pointer[c_int] = ...
+            self, __vtbl_index: int, __name: str, __paramflags: tuple[_PF, ...] | None = ..., __iid: _CData | None = ...
         ) -> None: ...
 
     def __call__(self, *args: Any, **kwargs: Any) -> Any: ...