We should stop trying to record usage for cancelled subscriptoins

[travis]

Describe the bug

During the monthly billing run we generate many, many errors by trying to add usage to subscriptions that have been cancelled in Stripe.

To Reproduce
Check the Sentry errors or CloudWatch logs for the usagetable handler (eg https://storacha-it.sentry.io/issues/6023958039/?query=usagetable&referrer=issue-stream&statsPeriod=30d&stream_index=0)

Expected behavior
We need a bit of product input here, I think - it's not clear what should happen at a product level when a subscription is cancelled - should your data be deleted? Should we keep it around for a bit in case you come back? Should we warn you? There should be some consequence, and that consequence probably has some impact on the right way to fix this bug.

In the short term we could just check if a user's subscription has been cancelled in stripe in the "customer billing queue handler" and not continue on - we may also want to use that as a jumping off point for the additional steps we should take (see the paragraph above this)