Save Image with Metadata Custom Node No longer working

### Prerequisites

- [x] I am running the latest version of ComfyUI
- [x] I have searched existing issues to make sure this isn't a duplicate
- [x] I have tested with all custom nodes disabled ([see how](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled))

### What happened?

Error after latest release of frontend and ComfyUI

[ComfyUI Image Metadata Extension] WARNING: Positive prompt is empty!
[ComfyUI Image Metadata Extension] WARNING: Steps are empty, full metadata won't be added!
[ComfyUI Image Metadata Extension] WARNING: Seed not found in pnginfo_dict!

Node is:

https://github.com/edelvarden/comfyui_image_metadata_extension

### Steps to Reproduce

1.
2.
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### How is this affecting you?

Crashes ComfyUI completely

### ComfyUI Frontend Version

1.28.8

### Browser

Edge

### Console Errors

```javascript

```

### Logs

```shell

```

### Additional Context

_No response_

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-6526-Save-Image-with-Metadata-Custom-Node-No-longer-working-29f6d73d365081dd84f4d3ad6cb5910b) by [Unito](https://www.unito.io)