Creates a zip of session_latest dir with test name and timestamp upon python test failure. Writes to dir specified by env var `RAY_TEST_FAILURE_LOGS_DIR`. Noop if env var does not exist.
Downstream consumer (e.g. CI) can upload all created artifacts in this dir. Thereby, PR submitters can more easily debug their CI failures, especially if they can't repro locally.
Limitations:
- a conftest.py file importing the main ray conftest.py needs to be present in same dir as test. This presents a challenge for e.g. dashboard tests which are highly scattered
