Delete XRT from the main branch (#5240)
* Delete XRT from the main branch
* Remove dead import
* formatting
* Remove disable_xrt build option
* Fix runtime init
* Revert "Remove disable_xrt build option"
This reverts commit ba312e76e069bef40c8f9803a672b29409862804.
* Add disable XRT option back
* formatting
* Prune mesh service
* Remove obsolete test
* Remove other run server script
* Remove XRT config
* Update PJRT default device test
* Add a file I forgot to save
* if using_pjrt -> @requires_pjrt
* Remove irrelevant test case
* Remove XRT env vars
* fix md link
* formatting
* Remove extra `requires_pjrt`
* merge conflicts
* Add other autocast back
