CI test linux://rllib:test_learner_group_async_update is flaky

[can-anyscale]

CI test linux://rllib:test_learner_group_async_update is flaky. Recent failures:
- https://buildkite.com/ray-project/postmerge/builds/7948#0194ade3-e11e-424f-a228-33ced75912d5
- https://buildkite.com/ray-project/postmerge/builds/7921#01949c14-3c46-4c09-945e-f847fae12c82
- https://buildkite.com/ray-project/postmerge/builds/7880#01948efc-f684-48fc-b4e9-5e38d1395ed2

DataCaseName-linux://rllib:test_learner_group_async_update-END
Managed by OSS Test Policy

[can-anyscale]

CI test linux://rllib:test_learner_group_async_update is flaky. Recent failures:
- https://buildkite.com/ray-project/postmerge/builds/7948#0194ade3-e11e-424f-a228-33ced75912d5
- https://buildkite.com/ray-project/postmerge/builds/7921#01949c14-3c46-4c09-945e-f847fae12c82
- https://buildkite.com/ray-project/postmerge/builds/7880#01948efc-f684-48fc-b4e9-5e38d1395ed2

DataCaseName-linux://rllib:test_learner_group_async_update-END
Managed by OSS Test Policy

[can-anyscale]

Test passed on latest run: https://buildkite.com/ray-project/postmerge/builds/7968#0194b0ad-f45d-4465-9f6d-1afc053e959d

[can-anyscale]

CI test linux://rllib:test_learner_group_async_update is consistently_failing. Recent failures:
- https://buildkite.com/ray-project/postmerge/builds/8001#0194be87-1319-444f-9fe1-2c26a0f59a20
- https://buildkite.com/ray-project/postmerge/builds/8001#0194be31-deea-428c-af0d-507be431eee3
- https://buildkite.com/ray-project/postmerge/builds/7948#0194ade3-e11e-424f-a228-33ced75912d5
- https://buildkite.com/ray-project/postmerge/builds/7921#01949c14-3c46-4c09-945e-f847fae12c82

DataCaseName-linux://rllib:test_learner_group_async_update-END
Managed by OSS Test Policy

[can-anyscale]

Test passed on latest run: https://buildkite.com/ray-project/postmerge/builds/8003#0194bf0f-9dd2-4f27-8f87-01f14a932497