test: `flaky test_results.py::test_result_reduce_ddp` terminated with signal SIGABRT

[kaiyaok2]

Bug description

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

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

To address this, the test could be marked flaky.

Background

We are evaluating how our tool for test prioritization could find test failures faster in your project. During a CI rerun for commit 7322d63bef2cf1a0439f8b19b545cd4a89da62b0, we encountered the failure of this test, which you can see in this log: GitHub Actions Log.

What version are you seeing the problem on?

master

How to reproduce the bug

Error messages and logs

# Error messages and logs here please

Environment

Current environment

#- PyTorch Lightning Version (e.g., 2.5.0):
#- PyTorch Version (e.g., 2.5):
#- Python version (e.g., 3.12):
#- OS (e.g., Linux):
#- CUDA/cuDNN version:
#- GPU models and configuration:
#- How you installed Lightning(`conda`, `pip`, source):

More info

No response