Update test_results.py

[kaiyaok2]

What does this PR do?

Fixes #xxx

The test tests/tests_pytorch/core/test_results.py::test_result_reduce_ddp fails intermittently due to chance, similar to the one addressed in #20537, with the error:

torch.multiprocessing.spawn.ProcessExitedException: process 0 terminated with signal SIGABRT

To address this, the test should also be marked flaky.

Background

We are researchers working on test case prioritization and have integrated our tool into GitHub CI. During a CI run for commit 7322d63bef2cf1a0439f8b19b545cd4a89da62b0, we encountered this failure. You can find the logs here: GitHub Actions Log.

Before submitting

• Was this discussed/agreed via a GitHub issue? (not for typos and docs)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure your PR does only one thing, instead of bundling different changes together?
• Did you verify new and existing tests pass locally with your changes?

PR review

Anyone in the community is welcome to review the PR.
Before you start reviewing, make sure you have read the review guidelines. In short, see the following bullet-list:

Reviewer checklist

• Is this pull request ready for review? (if not, please submit in draft mode)
• Check that all items from Before submitting are resolved
• Make sure the title is self-explanatory and the description concisely explains the PR
• Add labels and milestones (and optionally projects) to the PR so it can be classified