gtk-ng: fix missing progress_report action

src/apprt/gtk-ng/class/application.zig

@@ -381,6 +381,7 @@ pub const Application = extern struct {
             .check_for_updates,
             .undo,
             .redo,
+            .progress_report,
             => {
                 log.warn("unimplemented action={}", .{action});
                 return false;