[gtk4] Fix file chooser and open uri portal close.
This makes closing a portal file chooser work.
Fixes the GTK4 bits of #6225 (closed).
Same fix for gtkopenuriportal. The other instance of this pattern in gtkapplication-dbus.c does it right.
This makes closing a portal file chooser work.
Fixes the GTK4 bits of #6225 (closed).
Same fix for gtkopenuriportal. The other instance of this pattern in gtkapplication-dbus.c does it right.