Crash on close if Export dialog undocked

Steps to reproduce:

• open Inkscape
• open Export dialog (Ctrl+Shift+E)
• Undock dialog
• Closed the app

What happened?

• crash yadee_inkscape_backtrace.txt

What should have happened?

• No crash

Sample attachments: inkscape-bug-001

image_2022-05-23_020604573

Version info

Inkscape 1.2 (dc2aedaf03, 2022-05-15)

    GLib version:     2.72.1
    GTK version:      3.24.33
    glibmm version:   2.66.4
    gtkmm version:    3.24.6
    libxml2 version:  2.9.14
    libxslt version:  1.1.35
    Cairo version:    1.17.6
    Pango version:    1.50.7
    HarfBuzz version: 4.2.1

    OS version:       Windows 10 2004