### 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.
set_wrap_controls(true);
	set_visible(false);
	set_transient(true);
	set_flag(FLAG_BORDERLESS, true);
	set_flag(FLAG_RESIZE_DISABLED, true);
	set_flag(FLAG_POPUP, true);
	connect("window_input", callable_mp(this, &Popup::_input_from_window));
}
Popup::~Popup() {
}
Size2 PopupPanel::_get_contents_minimum_size() const {
	Size2 ms;
	for (int i = 0; i < get_child_count(); i++) {
		Control *c = Object::cast_to<Control>(get_child(i));
		if (!c || c == panel) {
			continue;
		}
		if (c->is_set_as_top_level()) {
			continue;
		}
		Size2 cms = c->get_combined_minimum_size();
		ms.x = MAX(cms.x, ms.x);
		ms.y = MAX(cms.y, ms.y);
	}
	return ms + theme_cache.panel_style->get_minimum_size();
}
void PopupPanel::_update_child_rects() {