Add Windows 11 support to get_windows_version()

reported downstream https://gitlab.com/inkscape/inkscape/-/issues/2648#note_629269188

Summary:

Copy the debug-information from Inkscape 1.1 (c68e22c387, 2021-05-23) on a Windows 11 Version 21H2 (Build22000.71) reports wrongly Windows 10 2009

Steps to reproduce:

• press on the in Inkscpae

What happened?

Inkscape 1.1 (c68e22c387, 2021-05-23)

    GLib version:     2.68.2
    GTK version:      3.24.29
    glibmm version:   2.66.0
    gtkmm version:    3.24.3
    libxml2 version:  2.9.12
    libxslt version:  1.1.34
    Cairo version:    1.17.4
    Pango version:    1.48.5
    HarfBuzz version: 2.8.1
    Poppler version:  20.12.1

    OS version:       Windows 10 2009

What should have happened?

    OS version:       Windows 11 21H2 

Version info