qga-win: Detect Windows 11 by build number

Windows 10 and 11 have the same major and minor versions.
So, the only way to determine the correct version is to
use the build number.

After this commit, the guest agent will return the proper
"version" and "version-id" for Windows 11. The "pretty-name"
is read from the registry and will be incorrect until the
MS updates the registry. We only can create some workaround
and replace 10 to 11.

Signed-off-by: Kostiantyn Kostiuk <konstantin@daynix.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Kostiantyn Kostiuk <kkostiuk@redhat.com>