Subgraph widgets of certain custom nodes cannot be modified

### Prerequisites

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

### What happened?

When making a subgraph that accepts the inputs of a [CropAndStitch node](https://github.com/lquesada/ComfyUI-Inpaint-CropAndStitch/), the widgets that appear on the subgraph are unable to be modified, neither by the arrows nor by inputting a concrete value. The only way to get around this is by creating a Primitive node that connects to the widget on the Subgraph, not only rendering the widget pointless, but also doesn't inherit the min or max values or increment value of the original widget.

This used to work on an older version of ComfyUI, but I have updated since then and cannot recall on what version it was last working.

Example subgraph:

Only the widgets that belong to the KSampler can be modified, the ones from the CropAndStitch node are unable to be changed:

The developer of the node [mentioned on a separate issue ](https://github.com/lquesada/ComfyUI-Inpaint-CropAndStitch/issues/163) that this is a problem with Subgraphs, which is why I'm reporting this issue here, since this could be affecting other custom nodes as well.

### Steps to Reproduce

1. Create a Subgraph containing a CropAndStitch node, linking one of its widget inputs.
2. Attempt to modify the widgets in the Subgraph.
3. The widget values will not change.

### How is this affecting you?

Feature doesn't work as expected

### ComfyUI Frontend Version

v1.42.15

### Browser

Chrome/Chromium

### Console Errors

```javascript

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### Logs

```shell

```

### Additional Context

_No response_

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-12054-Subgraph-widgets-of-certain-custom-nodes-cannot-be-modified-3596d73d365081d18041e0e59b550ee7) by [Unito](https://www.unito.io)