WanVideoModelLoader: Can't import SageAttention after trying to install ultravico

### 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

Hello,

I am running into the same error reported here:
`Can't import SageAttention: No module named 'sageattention'`

I attempted to follow the solution to install the 'ultravico' package via git (which seems to be the intended fix), but I received the following error, which prevents the installation:

fatal: repository [https://github.com/kijai/ultravico/](https://www.google.com/url?sa=E&q=https%3A%2F%2Fgithub.com%2Fkijai%2Fultravico%2F) not found

### Actual Behavior

code
Code
This error indicates that the repository does not exist or is not public, and because of this, the SageAttention module cannot be installed in the environment.

Could you please verify if the link to the `ultravico` repository is correct/public, or if the module needs to be included directly within the `ComfyUI-WanVideoWrapper` code?

Thank you for your time and work on this Custom Node!


### Steps to Reproduce

This error indicates that the repository does not exist or is not public, and because of this, the SageAttention module cannot be installed in the environment.

Could you please verify if the link to the `ultravico` repository is correct/public, or if the module needs to be included directly within the `ComfyUI-WanVideoWrapper` code?

Thank you for your time and work on this Custom Node!

### Debug Logs

```powershell
This error indicates that the repository does not exist or is not public, and because of this, the SageAttention module cannot be installed in the environment.

Could you please verify if the link to the `ultravico` repository is correct/public, or if the module needs to be included directly within the `ComfyUI-WanVideoWrapper` code?

Thank you for your time and work on this Custom Node!
```

### Other

_No response_