use-sage-attention3 command line argument is missing

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

Here it says that sage attention 3 was added:
https://github.com/Comfy-Org/ComfyUI/releases/tag/v0.8.0

But in source code `cli_args.py` there is no mention of sage attention 3 therefore this command line argument does nothing.

### Actual Behavior

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### Steps to Reproduce

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### Debug Logs

```powershell
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```

### Other

_No response_

Start in cli_args.py and compare its attention-related command-line arguments with the v0.8.0 release note mentioning Sage Attention 3. Confirm how the use-sage-attention3 option is expected to be registered and verify that the command-line argument is recognized and no longer does nothing.

Written by the indexing model from the issue text.