Update Vertex AI guide to remove note con cuda toolkit 11

We have a this note: 

<img width="775" height="364" alt="Image" src="https://github.com/user-attachments/assets/67b5ef4c-cce2-48ae-a761-334fc28a16ce" />

I believe this is no longer the case, that being said, the default env is broken at the moment, see #709 . Once that is fixed, make sure to test the installation instructions via pip and update accordingly. 