gtkmain: Release the active state on GDK_GRAB_BROKEN

This is handled internally here, but misses broken grabs. The active
state should be dropped just as if the button were released.

Fixes: https://gitlab.gnome.org/GNOME/gtk/-/issues/2665

gtk/gtkmain.c

@@ -1621,6 +1621,7 @@ handle_pointing_event (GdkEvent *event)
       target = gtk_window_lookup_effective_pointer_focus_widget (toplevel,
                                                                  device,
                                                                  sequence);
+      set_widget_active_state (target, TRUE);
       break;
     default:
       g_assert_not_reached ();