wgl: Switch to Win10 version defines to enable usage of Win10 WGL callbacks

Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6228>

scons/gallium.py

@@ -399,8 +399,8 @@ def generate(env):
             #'_UNICODE',
             #'UNICODE',
             # http://msdn.microsoft.com/en-us/library/aa383745.aspx
-            ('_WIN32_WINNT', '0x0601'),
-            ('WINVER', '0x0601'),
+            ('_WIN32_WINNT', '0x0A00'),
+            ('WINVER', '0x0A00'),
         ]
         if gcc_compat:
             cppdefines += [('__MSVCRT_VERSION__', '0x0700')]