### Godot version

v4.0 rc6

### System information

Windows 10

### Issue description

When using a ViewportTexture from a SubViewport on a TextureRect, it throws errors after running the scene once and then switching scenes in the editor.
![Pasted image 20230227212626](https://user-images.githubusercontent.com/44676282/221680047-984fa03e-33d1-4856-9a7f-1700b28423cf.png)


### Steps to reproduce

Run the canvas-scene once.
Switch to another scene in the editor.
Switch back to the canvas-scene

### Minimal reproduction project

[ViewportTextureError.zip](https://github.com/godotengine/godot/files/10844099/ViewportTextureError.zip)

case SUB_WINDOW_RESIZE_TOP_RIGHT: {
						diff.x = MAX(diff.x, -limit.x);
						diff.y = MIN(diff.y, limit.y);
						r.position.y += diff.y;
						r.size.y -= diff.y;
						r.size.x += diff.x;
					} break;
					case SUB_WINDOW_RESIZE_LEFT: {
						diff.x = MIN(diff.x, limit.x);
						diff.y = 0;
						r.position += diff;
						r.size -= diff;
					} break;
					case SUB_WINDOW_RESIZE_RIGHT: {
						diff.x = MAX(diff.x, -limit.x);
						r.size.x += diff.x;
					} break;
					case SUB_WINDOW_RESIZE_BOTTOM_LEFT: {
						diff.x = MIN(diff.x, limit.x);
						diff.y = MAX(diff.y, -limit.y);
						r.position.x += diff.x;
						r.size.x -= diff.x;
						r.size.y += diff.y;
					} break;
					case SUB_WINDOW_RESIZE_BOTTOM: {
						diff.y = MAX(diff.y, -limit.y);
						r.size.y += diff.y;
					} break;
					case SUB_WINDOW_RESIZE_BOTTOM_RIGHT: {
						diff.x = MAX(diff.x, -limit.x);