Investigate flaky tests_open_granular[azure]

[pared]

tests/func/test_api.py::test_open_granular[azure] seems to be failing sometimes (example). We need to fix it.

[efiop]

Looks like it is simply racing a bit. The container is not ready when this is called. Just need to add a flaky decorator.

[skshetry]

@efiop, better to wait for and timeout than adding flaky, as rerunning it still has chances of the container not being ready.

[ju0gri]

I'll be looking into this issue.

[efiop]

@skshetry Great point! Ideally we need some retrying logic in our trees, but that is a much bigger task. Just slapping a flaky decorator should do the trick for now.