"Execute to selected output nodes" actually executes the entire workflow.

### 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?

A few versions ago was added a little button called "Execute to selected output nodes". From the description, I (and I guess everyone else too) understood it as something meant to run the workflow only for that specific node. But when you actually use it, the whole workflow gets executed anyway.

### Steps to Reproduce

Create any workflow with a flow that branches into parallel flows and try to execute only one of the branches using that button.

### How is this affecting you?

Feature doesn't work as expected

### ComfyUI Frontend Version

1.27.1

### Browser

Chrome/Chromium

### Console Errors

```javascript

```

### Logs

```shell

```

### Additional Context

https://github.com/user-attachments/assets/fe143f7c-a32e-4585-8c35-2aff293854e2

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-5394-Execute-to-selected-output-nodes-actually-executes-the-entire-workflow-2666d73d365081da85e8fa62949b4e05) by [Unito](https://www.unito.io)