bug#51955: screenkey cannot be launched

[Ricardo Wurmus <rekado@elephly.net>]

I just tried to run screenkey (from the python-screenkey package) 
on core-updates-frozen (commit 
b41d3fa9834c2932b654111401567058d61aa6e1).  This is what happens:

--8<---------------cut here---------------start------------->8---
/gnu/store/qymgzlpavhsliylalyd3d3rj5ri8q373-python-screenkey-1.4/bin/screenkey
Traceback (most recent call last):
  File 
  "/gnu/store/qymgzlpavhsliylalyd3d3rj5ri8q373-python-screenkey-1.4/bin/.screenkey-real", 
  line 118, in <module>
    main()
  File 
  "/gnu/store/qymgzlpavhsliylalyd3d3rj5ri8q373-python-screenkey-1.4/bin/.screenkey-real", 
  line 110, in main
    app = sc.Screenkey(logger=logger, options=options, 
    show_settings=args.show_settings)
  File 
  "/gnu/store/qymgzlpavhsliylalyd3d3rj5ri8q373-python-screenkey-1.4/lib/python3.9/site-packages/Screenkey/screenkey.py", 
  line 92, in __init__
    Gtk.Window.__init__(self, Gtk.WindowType.POPUP)
  File 
  "/gnu/store/5frly276xr7gl0cyfmcl27y1r3kcnhkp-python-pygobject-3.40.1/lib/python3.9/site-packages/gi/overrides/Gtk.py", 
  line 522, in __init__
    _window_init(self, *args, **kwargs)
  File 
  "/gnu/store/5frly276xr7gl0cyfmcl27y1r3kcnhkp-python-pygobject-3.40.1/lib/python3.9/site-packages/gi/overrides/__init__.py", 
  line 319, in new_init
    return super_init_func(self, **new_kwargs)
TypeError: gobject `Screenkey+screenkey+Screenkey' doesn't support 
property `type'
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-- 
Ricardo