### Godot version

v4.0.beta15.official [4fa6edc88]

### System information

Windows 11

### Issue description

When drawing a polygon in the editor, several duplicate vertices are added to the polygon array for each click.  In the image below, I clicked three times to draw the triangle, but got 10 entries.  The number you get varies, though I don't know why; I've seen hundreds of points from drawing a hexagon.  I tested it with a Polygon2D, a CollisionPolygon2D, and a CollisionPolygon3D; the issues occurs with all of them.  It later occurred to me that this might happen with a Curve2D as well, and it does.

![image](https://user-images.githubusercontent.com/2808851/214926182-b8609b87-85a1-4a08-8017-be4eeec912c6.png)


### Steps to reproduce

Add a node that has a Polygon or Curve resource, such as a Polygon2D, draw some points, then check the PackedVector2Array resource.

### Minimal reproduction project

N/A
for (int i = p_start; i < editor_data.get_edited_scene_count(); i++) {
		if (!editor_data.get_edited_scene_root(i)) {
			continue;
		}
		bool unsaved = EditorUndoRedoManager::get_singleton()->is_history_unsaved(editor_data.get_scene_history_id(i));
		if (unsaved) {
			String scene_filename = editor_data.get_edited_scene_root(i)->get_scene_file_path();
			if (p_valid_filename && scene_filename.length() == 0) {
				continue;
			}
			return i;
		}
	}
	return -1;
}
void EditorNode::_exit_editor(int p_exit_code) {