### 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.
#include "popup.h"
#include "core/config/engine.h"
#include "core/os/keyboard.h"
#include "scene/gui/panel.h"
void Popup::_input_from_window(const Ref<InputEvent> &p_event) {
	Ref<InputEventKey> key = p_event;
	if (get_flag(FLAG_POPUP) && key.is_valid() && key->is_action_pressed(SNAME("ui_cancel"), false, true)) {
		_close_pressed();
	}
}
void Popup::_initialize_visible_parents() {
	if (is_embedded()) {
		visible_parents.clear();
		Window *parent_window = this;
		while (parent_window) {
			parent_window = parent_window->get_parent_visible_window();
			if (parent_window) {
				visible_parents.push_back(parent_window);
				parent_window->connect("focus_entered", callable_mp(this, &Popup::_parent_focused));
				parent_window->connect("tree_exited", callable_mp(this, &Popup::_deinitialize_visible_parents));
			}
		}
	}
}
void Popup::_deinitialize_visible_parents() {