### 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;
	if (is_inside_tree() && window_id != DisplayServer::MAIN_WINDOW_ID) {
		ERR_FAIL_MSG("Only the root window can set and use font oversampling.");
	}
	use_font_oversampling = p_oversampling;
	_update_viewport_size();
}
bool Window::is_using_font_oversampling() const {
	ERR_READ_THREAD_GUARD_V(false);
	return use_font_oversampling;
}
DisplayServer::WindowID Window::get_window_id() const {
	ERR_READ_THREAD_GUARD_V(DisplayServer::INVALID_WINDOW_ID);
	if (embedder) {
		return parent->get_window_id();
	}
	return window_id;
}
void Window::set_mouse_passthrough_polygon(const Vector<Vector2> &p_region) {
	ERR_MAIN_THREAD_GUARD;
	mpath = p_region;
	if (window_id == DisplayServer::INVALID_WINDOW_ID) {
		return;
	}
	DisplayServer::get_singleton()->window_set_mouse_passthrough(mpath, window_id);
}
Vector<Vector2> Window::get_mouse_passthrough_polygon() const {
	return mpath;
}
void Window::set_wrap_controls(bool p_enable) {