Currently this class defines
    public static final WindowsVersion WINDOWS_95 = new WindowsVersion(4, 0);
    public static final WindowsVersion WINDOWS_98 = new WindowsVersion(4, 10);
    public static final WindowsVersion WINDOWS_ME = new WindowsVersion(4, 90);
    public static final WindowsVersion WINDOWS_2000 = new WindowsVersion(5, 0);
    public static final WindowsVersion WINDOWS_XP = new WindowsVersion(5, 1);
    public static final WindowsVersion WINDOWS_2003 = new WindowsVersion(5, 2);
    public static final WindowsVersion WINDOWS_VISTA = new WindowsVersion(6, 0);
    public static final WindowsVersion WINDOWS_7 = new WindowsVersion(6, 1);

So no Windows 8, Windows 10, or Windows 11

And in addition, I'm not sure how much we need some of the old versions,
although tests that are essentially "> Windows 95", and "< Windows_2000" may still have some usefulness, but it would also be good to look at how
they are being used, and even though XP may not be supported it was
the version in which some behaviour changed.
So I'd be inclined to leave those old versions at least for completeness
but examine how they are being used.
Or possibly we could drop some and just look for a later version.
Or possibly it might point to some code that we don't need any more.
Windows Classic L&F is an example but if we can't get XPStyles .. we may
need it as a fall back.