### 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
}
			img->convert(Image::FORMAT_RGB8);
			
			String temp_path = EditorPaths::get_singleton()->get_cache_dir();
			String cache_base = ProjectSettings::get_singleton()->globalize_path(p_file).md5_text();
			cache_base = temp_path.path_join("resthumb-" + cache_base);
			
			post_process_preview(img);
			img->save_png(cache_base + ".png");
		}
	}
	save.step(TTR("Saving Scene"), 4);
	_save_scene(p_file, p_idx);
	if (!singleton->cmdline_export_mode) {
		EditorResourcePreview::get_singleton()->check_for_invalidation(p_file);
	}
}
bool EditorNode::_validate_scene_recursive(const String &p_filename, Node *p_node) {
	for (int i = 0; i < p_node->get_child_count(); i++) {
		Node *child = p_node->get_child(i);
		if (child->get_scene_file_path() == p_filename) {
			return true;
		}
		if (_validate_scene_recursive(p_filename, child)) {
			return true;
		}
	}
	return false;
}
int EditorNode::_save_external_resources() {