Update docs

[tolgacangoz]

On this page, "https://huggingface.co/docs/diffusers/main/en/optimization/torch2.0", it says "... as the stable version is yet to be released.".

[sayakpaul]

Thanks for pointing it out. I think, in general, the Torch 2.0 doc needs some modifications.

@pcuenca, could you maybe address it?

[pcuenca]

I just merged #2764 to update the PyTorch 2 docs. @StandardAI thanks a lot, and feel free to open a new issue if you see other problems :)