### 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.
if (!wrap_controls) {
		updating_embedded_window = true;
		call_deferred(SNAME("_update_embedded_window"));
	} else {
		child_controls_changed();
	}
}
void Window::_update_embedded_window() {
	if (!updating_embedded_window) {
		return;
	}
	if (embedder) {
		embedder->_sub_window_update(this);
	};
	updating_embedded_window = false;
}
void Window::set_theme_type_variation(const StringName &p_theme_type) {
	ERR_MAIN_THREAD_GUARD;
	theme_type_variation = p_theme_type;
	if (is_inside_tree()) {
		notification(NOTIFICATION_THEME_CHANGED);
	}
}
StringName Window::get_theme_type_variation() const {