Assess AutoClass pricing implications

[charlie-costanzo]

In #2773, we identify two buckets that we want to move to cold storage (gtfs-data and gtfs-data-test). Since the ticket's creation, we've determined that applying GCP's AutoClass feature to these buckets may be the appropriate route forward.

Before implementing this, we'd like to have a sense of the pricing implications of configuring AutoClass on these buckets so that we can present the option to decision-makers.

It seems as though the pricing model favors initialization fees as opposed to long-term retrieval and usage fees. We will want to have a sense of what these costs will look like before sharing. (more details on GCP AutoClass pricing can be found in this comment)