portal version of async gtk_print_operation_run forgets to emit "done" signal
According to the documentation, a GtkPrintOperation can be run asynchronously and emit a "done" signal upon completion. However, this signal is never emitted if the print operation is executed through a portal and is cancelled.
This behavior can cause resource leaks as any cleanup operations that would normally happen in the signal handler would not occur. See this Evince bug for example.