Codemod service to disable and mark slow tests directly in PyTorch code base

[huydhn]

The mechanism to disable a test is sometimes "abused" to keep a test disable for a long time without any owner to work on fixing it. Although, this helps mitigate an flaky test well, it has several drawback:

• It makes thing harder to keep track, a test that is disabled directly in the code is much easier to see
• Closing a disabled issue is tricky Provide the range of commits where a disabled test is effectively disabled #4980

Ideally, we want to keep the current mechanism but limit it only to recently flaky tests, i.e. within 2 weeks. Anything older than that and has not yet been addressed should be disabled directly in the code. Doing this manually doesn't scale, so we need a better tool for this like a codemod service of sort.

cc @clee2000 @malfet @kit1980

[huydhn]

AI: It's better to be able to keep the test as XFAIL if possible or a special decorator like skipifFlaky