### 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_FAIL_COND(!tasks.has(p_task));
	Task &t = tasks[p_task];
	memdelete(t.vb);
	tasks.erase(p_task);
	if (tasks.is_empty()) {
		hide();
	} else {
		_popup();
	}
}
void ProgressDialog::_cancel_pressed() {