[runtime env] [CI] Skip flaky test_runtime_env_working_dir_2 tests on mac

[architkulkarni]

Why are these changes needed?

Some tests in test_runtime_env_working_dir_2 are passing on Linux but flaky on Mac. This test skips them on Mac to fix CI. The underlying issue #27562 will remain open until we fix the root cause and reenable them on Mac.

Related issue number

Checks

• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[shrekris-anyscale]

Stamp

[architkulkarni]

Mac tests:test_actor_failures flaky on master and unrelated
Docs linkcheck broken on master and unrelated
RLlib tune_lin_ucb_train_recsim_env flaky and unrelated
rllib:test_memory_leak_ppo flaky and unrelated
test_tune_restore and test_cluster flaky and unrelated
Windows:
serve:tutorial_rllib broken on master and unrelated
tests:test_client_library_integration, test_tensorflow broken and unrelated