Revert "Support PyTorch ROCm CI on Ubuntu18.04 (#31886)" (#31946)
Summary:
This reverts commit 4ee9c562188ae930cb2520cfce7805f55acaf968.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31946
Differential Revision: D19368391
Pulled By: bddppq
fbshipit-source-id: 63d032a5256ff4da7247fb1092be314c5b133eb6
