### 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
_find_and_save_edited_subresources(scene, processed, flags);
	for (int i = 0; i < scene->get_child_count(); i++) {
		Node *n = scene->get_child(i);
		if (n->get_owner() != editor_data.get_edited_scene_root()) {
			continue;
		}
		_save_edited_subresources(n, processed, flags);
	}
}
void EditorNode::_find_node_types(Node *p_node, int &count_2d, int &count_3d) {
	if (p_node->is_class("Viewport") || (p_node != editor_data.get_edited_scene_root() && p_node->get_owner() != editor_data.get_edited_scene_root())) {
		return;
	}
	if (p_node->is_class("CanvasItem")) {
		count_2d++;
	} else if (p_node->is_class("Node3D")) {
		count_3d++;
	}
	for (int i = 0; i < p_node->get_child_count(); i++) {
		_find_node_types(p_node->get_child(i), count_2d, count_3d);
	}
}
void EditorNode::_save_scene_with_preview(String p_file, int p_idx) {