fix: add favicon stub (#1511)

## Description
The VC-Frontend does not use favicon.ico. But some brousers try to
download it which leads to an error in the console.
<img width="625" alt="image"
src="https://github.com/user-attachments/assets/b5ebdac0-705f-41ed-8cd0-9c4997ca7bf1"
/>

This PR add favicon.ico stub.
## References
### Artifact URL: