### 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.
ERR_MAIN_THREAD_GUARD;
	set_visible(false);
}
void Window::set_visible(bool p_visible) {
	ERR_MAIN_THREAD_GUARD;
	if (visible == p_visible) {
		return;
	}
	if (!is_inside_tree()) {
		visible = p_visible;
		return;
	}
	ERR_FAIL_COND_MSG(get_parent() == nullptr, "Can't change visibility of main window.");
	visible = p_visible;
	
	updating_child_controls = false;
	Viewport *embedder_vp = get_embedder();
	if (!embedder_vp) {
		if (!p_visible && window_id != DisplayServer::INVALID_WINDOW_ID) {
			_clear_window();
		}
		if (p_visible && window_id == DisplayServer::INVALID_WINDOW_ID) {
			_make_window();
		}
	} else {
		if (visible) {
			embedder = embedder_vp;