gh-133580: Add missing exception to _sys_getwindowsversion_from_kernel32 (GH-133574)

Author: maxbachmann

Misc/NEWS.d/next/Windows/2025-05-07-13-04-22.gh-issue-133580.jBMujJ.rst

@@ -0,0 +1 @@
+Fix :func:`sys.getwindowsversion` failing without setting an exception when called on some WinAPI partitions.

Python/sysmodule.c

@@ -1643,6 +1643,7 @@ static PyObject *
 _sys_getwindowsversion_from_kernel32(void)
 {
 #ifndef MS_WINDOWS_DESKTOP
+    PyErr_SetString(PyExc_OSError, "cannot read version info on this platform");
     return NULL;
 #else
     HANDLE hKernel32;