Delete batch tensor (#18575)
Summary:
Deleting batch tensor since we are no longer maintaining the project and keeping it functional is blocking other improvements.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18575
Differential Revision: D14671126
Pulled By: eellison
fbshipit-source-id: b42d5b699c4d12171ed95e6d3a977532167f0d2c