test_retriever.py::test_dpr_embedding for Weaviate is flaky

[bogdankostic]

Describe the bug
This CI run failed due to Weaviate complaining that the used index is read-only. Therefore, writing documents and deleting the index resulted in an error. However, re-running the workflow resulted in all tests passing. We should make sure that the tests do not fail occasionally for no reason.

Error message

weaviate.exceptions.UnexpectedStatusCodeException: Add property to class! Unexpected status code: 422, with response body: {'error': [{'message': 'add property to shard "yR58cqXtj7Gq": store is read-only'}]}

weaviate.exceptions.UnexpectedStatusCodeException: Delete class from schema! Unexpected status code: 400, with response body: {'error': [{'message': "delete idx for class 'HaystackTest': drop index haystacktest: delete shard haystacktest_yR58cqXtj7Gq: store is read-only"}]}

[sjrl]

Hey @bogdankostic this is blocking my PR #2856 and it failed again after trying to rerun just the failed job. Is there a recommendation for how to work around this?