Subgraph combo/dropdown broken in nodes2.0

### Prerequisites

- [x] I am running the latest version of ComfyUI
- [x] I have custom nodes enabled

### What happened?

https://github.com/user-attachments/assets/9b121bc1-17f2-4615-8c3a-8992887d0cc3

### Steps to Reproduce

1. yes
2.
3.

### How is this affecting you?

Feature doesn't work as expected

### ComfyUI Frontend Version

1.40.8

### Browser

Chrome/Chromium

### Console Errors

```javascript

```

### Logs

```shell

```

### Additional Context

_No response_

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-9012-Subgraph-combo-dropdown-broken-in-nodes2-0-30d6d73d365081568d45d46ec6a6390c) by [Unito](https://www.unito.io)