Remove no-fork workaround for running tests with ROCm (#19436)
Summary:
This should have been fixed in newest ROCm version.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19436
Reviewed By: ezyang
Differential Revision: D15004685
Pulled By: bddppq
fbshipit-source-id: 19fd4cca94c914dc54aabfbb4e62b328aa348a35
