[XLA hash update] update the pinned xla hash (#78144)
This PR is auto-generated nightly by [this action](https://github.com/pytorch/pytorch/blob/master/.github/workflows/update-xla-commit-hash.yml).
Update the pinned xla hash from `7f96fbf6f7e37810a805c741416e7c54ae65c8cd` to `bb43e8a7048c008e5379f3d8ef7027496fbce0ef`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78144
Approved by: https://github.com/clee2000
