Removes this item from the view scene.

def removeFromScene(self):
        """
        Removes this item from the view scene.
        """
        gantt = self.ganttWidget()
        if not gantt:
            return
        
        scene = gantt.viewWidget().scene()
        
        scene.removeItem(self.viewItem())
        for target, viewItem in self._dependencies.items():
            target._reverseDependencies.pop(self)
            scene.removeItem(viewItem)