pipewire: Destroy the pipewire outputs at shutdown

Seems like we are missing destroying the pipewire outputs on the shutdown
path; this follow-ups with remoting plug-in as well.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
(cherry picked from commit 278fe4d7d47c7828d42047f4c910f1d815d32b80)

pipewire/pipewire-plugin.c

@@ -631,10 +631,14 @@ weston_pipewire_destroy(struct wl_listener *l, void *data)
 {
 	struct weston_pipewire *pipewire =
 		wl_container_of(l, pipewire, destroy_listener);
+	struct pipewire_output *p_output, *p_output_next;
 
 	weston_log_scope_destroy(pipewire->debug);
 	pipewire->debug = NULL;
 
+	wl_list_for_each_safe(p_output, p_output_next, &pipewire->output_list, link)
+		pipewire_output_destroy(p_output->output);
+
 	wl_event_source_remove(pipewire->loop_source);
 	pw_loop_leave(pipewire->loop);
 	pw_loop_destroy(pipewire->loop);