### 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;
	Size2i min_size_clamped = _clamp_limit_size(p_min_size);
	if (min_size == min_size_clamped) {
		return;
	}
	min_size = min_size_clamped;
	_validate_limit_size();
	_update_window_size();
}
Size2i Window::get_min_size() const {
	ERR_READ_THREAD_GUARD_V(Size2i());
	return min_size;
}
void Window::set_mode(Mode p_mode) {
	ERR_MAIN_THREAD_GUARD;
	mode = p_mode;
	if (embedder) {
		embedder->_sub_window_update(this);
	} else if (window_id != DisplayServer::INVALID_WINDOW_ID) {
		DisplayServer::get_singleton()->window_set_mode(DisplayServer::WindowMode(p_mode), window_id);
	}
}
Window::Mode Window::get_mode() const {
	ERR_READ_THREAD_GUARD_V(MODE_WINDOWED);
	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
		mode = (Mode)DisplayServer::get_singleton()->window_get_mode(window_id);
	}
	return mode;
}
void Window::set_flag(Flags p_flag, bool p_enabled) {