Fill and stroke dialog - radio boxes can be uncheked

Summary:

... (write here)

Steps to reproduce:

• open Inkscape
• Create a rectangle
• open fs dialog
• click twice on flat color chekbox

What happened?

What should have happened?

second click on radio button should have no effect on state of this button should still stay selected

Sample attachments:

Version info

inkscape 1.4.2
Inkscape 1.5-dev (e581b97, 2025-05-13, custom)

                      Compile  (Run)
    GLib version:     2.82.0
    GTK version:      4.14.5 (4.14.5)
    glibmm version:   2.80.1
    gtkmm version:    4.14.0
    libxml2 version:  2.12.9
    libxslt version:  1.1.42
    Cairo version:    1.18.0 (1.18.0)
    Pango version:    1.54.0 (1.54.0)
    HarfBuzz version: 9.0.0 (9.0.0)
    Poppler version:  24.08.0

    OS version:       Windows 11 24H2