### 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)

ERR_READ_THREAD_GUARD_V(SHADOW_ATLAS_QUADRANT_SUBDIV_DISABLED);
	ERR_FAIL_INDEX_V(p_quadrant, 4, SHADOW_ATLAS_QUADRANT_SUBDIV_DISABLED);
	return positional_shadow_atlas_quadrant_subdiv[p_quadrant];
}
Ref<InputEvent> Viewport::_make_input_local(const Ref<InputEvent> &ev) {
	if (ev.is_null()) {
		return ev; 
	}
	Transform2D ai = get_final_transform().affine_inverse();
	return ev->xformed_by(ai);
}
Vector2 Viewport::get_mouse_position() const {
	ERR_READ_THREAD_GUARD_V(Vector2());
	if (!is_directly_attached_to_screen()) {
		
		
		return gui.last_mouse_pos;
	} else if (DisplayServer::get_singleton()->has_feature(DisplayServer::FEATURE_MOUSE)) {
		Transform2D xform = get_screen_transform_internal(true);
		if (xform.determinant() == 0) {
			
			return Vector2();
		}
		return xform.affine_inverse().xform(DisplayServer::get_singleton()->mouse_get_position());
	} else {
		
		return get_screen_transform_internal().affine_inverse().xform(Input::get_singleton()->get_mouse_position());
	}
}
void Viewport::warp_mouse(const Vector2 &p_position) {