### 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)

if (path_cache == p_path) {
		return;
	}
	if (p_path.is_empty()) {
		p_take_over = false; 
	}
	ResourceCache::lock.lock();
	if (!path_cache.is_empty()) {
		ResourceCache::resources.erase(path_cache);
	}
	path_cache = "";
	Ref<Resource> existing = ResourceCache::get_ref(p_path);
	if (existing.is_valid()) {
		if (p_take_over) {
			existing->path_cache = String();
			ResourceCache::resources.erase(p_path);
		} else {
			ResourceCache::lock.unlock();
			ERR_FAIL_MSG("Another resource is loaded from path '" + p_path + "' (possible cyclic resource inclusion).");
		}
	}
	path_cache = p_path;
	if (!path_cache.is_empty()) {
		ResourceCache::resources[path_cache] = this;
	}
	ResourceCache::lock.unlock();
	_resource_path_changed();
}
String Resource::get_path() const {