[_ctypes] Add dllist() (#16143)

Author: srittau

stdlib/_ctypes.pyi

@@ -373,3 +373,7 @@ def Py_INCREF(o: _T, /) -> _T: ...
 def buffer_info(o: _CData | _CDataType | type[_CData | _CDataType], /) -> tuple[str, int, tuple[int, ...]]: ...
 def call_cdeclfunction(address: int, arguments: tuple[Any, ...], /) -> Any: ...
 def call_function(address: int, arguments: tuple[Any, ...], /) -> Any: ...
+
+# dllist() is available on Linux and other platforms like NetBSD
+if sys.version_info >= (3, 15) and sys.platform != "win32" and sys.platform != "darwin":
+    def dllist() -> list[str]: ...