[PyTorch][vulkan] Unify vtensor_from_vulkan to always return non-const ref (#59996)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59996
Just like D28811477 (https://github.com/pytorch/pytorch/commit/dce8697aeacd169ef318ed4068a334595ba123ce), there's no reason we can't give it this signature.
ghstack-source-id: 132566618
Test Plan: CI
Reviewed By: AshkanAliabadi
Differential Revision: D29119070
fbshipit-source-id: d049d49c38099eef6c96e8f69909827e64376097
