### Godot version

4.1.dev (dc625bcbfc5b587ba8867481ee7a1f6a567c25d0)

### System information

Mageia 9, Linux

### Issue description

When importing a project in current `master`, the following error is raised for each asset that gets imported:
```
Attempting to parent and popup a dialog that already has a parent.
```

It seems to be raised once per asset, caused by the progress dialog.

CC @bruvzg

### Steps to reproduce

- Import a new project in Godot that contains importable assets, e.g. https://github.com/RPicster/godot4-demo-desert-light

### Minimal reproduction project

See above.
GDCLASS(ProgressDialog, PopupPanel);
	struct Task {
		String task;
		VBoxContainer *vb = nullptr;
		ProgressBar *progress = nullptr;
		Label *state = nullptr;
	};
	HBoxContainer *cancel_hb = nullptr;
	Button *cancel = nullptr;
	HashMap<String, Task> tasks;
	VBoxContainer *main = nullptr;
	uint64_t last_progress_tick;
	static ProgressDialog *singleton;
	void _popup();
	void _cancel_pressed();
	bool canceled = false;
protected:
	void _notification(int p_what);
	static void _bind_methods();
public:
	static ProgressDialog *get_singleton() { return singleton; }
	void add_task(const String &p_task, const String &p_label, int p_steps, bool p_can_cancel = false);
	bool task_step(const String &p_task, const String &p_state, int p_step = -1, bool p_force_redraw = true);
	void end_task(const String &p_task);
	ProgressDialog();
};
#endif