[Bug] Fix history_length_with_fail_and_timeout::use_cache_2_false::history_responses_case_3_3 flaky test and re-enable

[Sushisource]

Fix this stupid test that consistently flakes in CI but is unreproducible locally. I've looked into this a few times already and it's incredibly hard to figure out what's going on despite it triggering like 75% of the time in CI.

Started a PR (with nothing interesting in it as of issue open time) here: https://github.com/temporalio/sdk-core/pull/749

[cretz]

Reopening, I believe this is still occurring regularly. Still seeing cases where the CI stops down with:

test core_tests::workflow_tasks::history_length_with_fail_and_timeout::use_cache_2_false::history_responses_case_3_3 has been running for over 60 seconds

Until the whole GH workflow times out