Clean up intern fast tests failures

[sonniki]

Interns have reported failures while running i fast_tests: see https://github.com/causify-ai/helpers/issues/392#issuecomment-2745413503 and below, https://github.com/causify-ai/helpers/issues/391#issuecomment-2746813006 and below. We should go over the failing tests:

• If some of them are expected to fail for users working on local computers (not on the server), e.g. tests for dockerized executables/tests with deps from AWS, we should pytest.skip them on the condition of is_external_dev() (to be added in https://github.com/causify-ai/helpers/issues/406).
• If some of them are expected to fail for some other reason, we could add a note to the intern dev setup doc about them so that those tests failing does not raise questions from the interns.

FYI @gpsaggese @samarth9008