Bundle lazy ts backend (#82384)
### Description
<!-- What did you change and why was it needed? -->
`libtorch.so` is missing `lazy/ts_backend`, which is breaking the XLA build/test pipeline.
### Issue
<!-- Link to Issue ticket or RFP -->
This currently blocks #82342 and #78182
### Testing
<!-- How did you test your change? -->
https://github.com/pytorch/pytorch/runs/7551019518?check_suite_focus=true
Pull Request resolved: https://github.com/pytorch/pytorch/pull/82384
Approved by: https://github.com/albanD
