Currently, running a smoke test for storage with pytest tests/test_smoke.py::TestStorageWithCredentials deletes all the sky managed storages created before runinng the test. This is due to subprocess.check_output(['sky', 'storage', 'delete', '-a']) ran from test_multiple_buckets_creation_and_deletion. This needs to be fixed so running the smoke test does not remove any other sky managed storages.

This can be reproduced by:

1. Create s3 storage with sky launch task.yaml
2. run pytest tests/test_smoke.py::TestStorageWithCredentials
3. confirm all the storage created from 1. gets deleted.