[ci][release] Known non-release-blocking issues tracking

[rickyyx]

List of flaky tests/failures that are known to be non-release blocking but might show up in CI failures/nightly failures. No cherry picks are expected for these failures. Release managers will ignore them in CI:

Release test known issues

• [release][CI] dataset_shuffle_random_shuffle_1tb failed  #29294
• [release] air_benchmark_tune_torch_mnist_large_gpu keeps timing out #29777
• [CI][release] long_running_horovod_tune_test failed  #29318 (fixed in master and non-release blocking)
• [Core][nightly-test] mark chaos_dataset_shuffle_push_based_sort_1tb unstable #29483 marked unstable
• [release][CI] rllib_learning_tests_a3c failed  #29093

CI build known issues

NA

---

These are ignored because:

• It's flaky and root causing in master is WIP or known to be non-release blocking.
• Test only bugs and fixing the test is non-trivial.

See individual issue for why this will not be fixed.

(This will be updated in-place continuously)

[rickyyx]

cc @zhe-thoughts