gh-133779: Revert Windows generation of pyconfig.h and go back to a static header. (GH-133966)

Extension builders must specify Py_GIL_DISABLED if they want to link to the free-threaded builds.
This was usually the case already, but this change guarantees it in all circumstances.

Include/Python.h

@@ -59,6 +59,14 @@
 #  include <intrin.h>             // __readgsqword()
 #endif
 
+// Suppress known warnings in Python header files.
+#if defined(_MSC_VER)
+// Warning that alignas behaviour has changed. Doesn't affect us, because we
+// never relied on the old behaviour.
+#pragma warning(push)
+#pragma warning(disable: 5274)
+#endif
+
 // Include Python header files
 #include "pyport.h"
 #include "pymacro.h"
@@ -138,4 +146,9 @@
 #include "cpython/pyfpe.h"
 #include "cpython/tracemalloc.h"
 
+// Restore warning filter
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
 #endif /* !Py_PYTHON_H */