add test_openmp to ROCM_BLACKLIST (#40204)
Summary:
This test is flaky for rocm platform. Add to blacklist until it can be further reviewed.
CC ezyang xw285cornell sunway513
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40204
Differential Revision: D22108295
Pulled By: xw285cornell
fbshipit-source-id: 802444a7b41260edcb6ce393237784f3e6c52a74
