### 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
ofs.x += s.x * 4;
				ofs.x += s.x;
			} break;
			case DOCK_SLOT_RIGHT_BR: {
				ofs.x += s.x * 4;
				ofs += s;
			} break;
		}
		Rect2 r(ofs, s);
		dock_select_rect[i] = r;
		r.position += Vector2(2, 5);
		r.size -= Vector2(4, 7);
		if (i == dock_select_rect_over_idx) {
			dock_select->draw_rect(r, used_selected);
		} else if (dock_slot[i]->get_tab_count() == 0) {
			dock_select->draw_rect(r, unused);
		} else {
			dock_select->draw_rect(r, used);
		}
		for (int j = 0; j < MIN(3, dock_slot[i]->get_tab_count()); j++) {
			int xofs = (r.size.width / 3) * j;
			Color c = used;
			if (i == dock_popup_selected_idx && (dock_slot[i]->get_current_tab() > 3 || dock_slot[i]->get_current_tab() == j)) {
				c = tab_selected;
			}
			dock_select->draw_rect(Rect2(2 + ofs.x + xofs, ofs.y, r.size.width / 3 - 1, 3), c);
		}
	}
}
void EditorNode::_save_docks() {