### 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.
cancel_hb->move_to_front();
	canceled = false;
	_popup();
	if (p_can_cancel) {
		cancel->grab_focus();
	}
}
bool ProgressDialog::task_step(const String &p_task, const String &p_state, int p_step, bool p_force_redraw) {
	ERR_FAIL_COND_V(!tasks.has(p_task), canceled);
	if (!p_force_redraw) {
		uint64_t tus = OS::get_singleton()->get_ticks_usec();
		if (tus - last_progress_tick < 200000) { 
			return canceled;
		}
	}
	Task &t = tasks[p_task];
	if (p_step < 0) {
		t.progress->set_value(t.progress->get_value() + 1);
	} else {
		t.progress->set_value(p_step);
	}
	t.state->set_text(p_state);
	last_progress_tick = OS::get_singleton()->get_ticks_usec();
	DisplayServer::get_singleton()->process_events();
#ifndef ANDROID_ENABLED
	Main::iteration(); 
#endif
	return canceled;
}
void ProgressDialog::end_task(const String &p_task) {