### 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 (transient_parent) {
		if (transient_parent->window_id != DisplayServer::INVALID_WINDOW_ID && window_id != DisplayServer::INVALID_WINDOW_ID) {
			DisplayServer::get_singleton()->window_set_transient(window_id, DisplayServer::INVALID_WINDOW_ID);
		}
		transient_parent->transient_children.erase(this);
		if (transient_parent->exclusive_child == this) {
			transient_parent->exclusive_child = nullptr;
		}
		transient_parent = nullptr;
	}
}
void Window::_make_transient() {