Revert "bpo-32592: Set Windows 8 as the minimum required version for API support (pythonGH-15951)"

This reverts commit 0b72ccf.

Author: zooba

Modules/posixmodule.c

@@ -13232,6 +13232,8 @@ os_cpu_count_impl(PyObject *module)
 {
     int ncpu = 0;
 #ifdef MS_WINDOWS
+    /* Declare prototype here to avoid pulling in all of the Win7 APIs in 3.8 */
+    DWORD WINAPI GetActiveProcessorCount(WORD group);
     ncpu = GetActiveProcessorCount(ALL_PROCESSOR_GROUPS);
 #elif defined(__hpux)
     ncpu = mpctl(MPC_GETNUMSPUS, NULL, NULL);

PC/pyconfig.h

@@ -135,9 +135,9 @@ WIN32 is still required for the locale module.
 #endif /* MS_WIN64 */
 
 /* set the version macros for the windows headers */
-/* Python 3.9+ requires Windows 8 or greater */
-#define Py_WINVER 0x0602 /* _WIN32_WINNT_WIN8 */
-#define Py_NTDDI NTDDI_WIN8
+/* Python 3.5+ requires Windows Vista or greater */
+#define Py_WINVER 0x0600 /* _WIN32_WINNT_VISTA */
+#define Py_NTDDI NTDDI_VISTA
 
 /* We only set these values when building Python - we don't want to force
    these values on extensions, as that will affect the prototypes and