Stop using gtk_widget_observe_children()
src/adw-preferences-group.c: priv->rows = gtk_widget_observe_children (GTK_WIDGET (priv->listbox));
src/adw-preferences-group.c: model = gtk_widget_observe_children (GTK_WIDGET (priv->listbox));
src/adw-preferences-page.c: model = gtk_widget_observe_children (GTK_WIDGET (priv->box));
These should go, instead AdwPreferencesPage
and AdwPreferencesGroup
should provide their own API.
Rationale: see docs for that function.