Remove obsolete checked defines

These are always defined when WINVER >= 0x0400; and we have it set to 0x0601
in solenv/gbuild/platform/windows.mk.

Change-Id: Ia1f6fa5589562fa710b4da3d288182d3f8a15e6b
Reviewed-on: https://gerrit.libreoffice.org/70348
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

include/postwin.h

@@ -53,17 +53,6 @@
 #undef Yield
 #undef mciSetCommand
 
-/* new StretchBlt() Modes (simpler names) */
-#ifndef STRETCH_ANDSCANS
-#define STRETCH_ANDSCANS        1
-#endif
-#ifndef STRETCH_ORSCANS
-#define STRETCH_ORSCANS         2
-#endif
-#ifndef STRETCH_DELETESCANS
-#define STRETCH_DELETESCANS     3
-#endif
-
 #if !defined INCLUDED_POSTWIN_H && defined __cplusplus
 #define INCLUDED_POSTWIN_H
 #endif