edgeDragAction: Drop grab-op-begin signal connection

This is done just to "reset" the gesture when a grab operation
begins. With grab ops being based on ClutterGrab now, the gesture
will be implicitly reset when these happen. This is unnecessary now.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2526>

js/ui/edgeDragAction.js

@@ -20,8 +20,6 @@ var EdgeDragAction = GObject.registerClass({
         this._allowedModes = allowedModes;
         this.set_n_touch_points(1);
         this.set_threshold_trigger_edge(Clutter.GestureTriggerEdge.AFTER);
-
-        global.display.connect('grab-op-begin', () => this.cancel());
     }
 
     _getMonitorRect(x, y) {