The Vercel Data Cache caches data across deployments, and we want to
check for updates in federated content, so let's revalidate the data
once a day.
It may be more efficient to revalidate on-demand, since we don't change
most of these sources once a day, but that requires setting up an API
endpoint (and figuring out how to authenticate it), so this is
quick-and-easy for now.
