Translate perf_infer_gpu one
See issue [https://github.com/https://github.com/huggingface/transformers/issues/17459]
Add Italian translation of perf_infer_gpu_one.mdx and update _toctree.yml.
It's my first pull request, so I hope it's ok

The GitHub related issue is [here](https://github.com/huggingface/transformers/issues/22294)

@omarespejel
@sgugger