Mark ROCm tests as flaky (#97259)
Before https://github.com/pytorch/pytorch/pull/96464, ROCm tests in trunk are already quite flaky https://hud.pytorch.org/reliability/pytorch/pytorch?jobName=trunk%20%2F%20linux-focal-rocm5.4.2-py3.8%20%2F%20test%20(default).
After https://github.com/pytorch/pytorch/pull/96464, there is a new group of flaky failures coming from functorch. So let's mark the test as flaky to monitor without impacting trunk.
Two flaky tests currently seeing in trunk are:
* https://github.com/pytorch/pytorch/issues/97256
* `functorch/test_memory_efficient_fusion.py` OOM
Pull Request resolved: https://github.com/pytorch/pytorch/pull/97259
Approved by: https://github.com/malfet, https://github.com/zou3519
