GitHub Actions cache is now scoped by repository

Cache entries stored in the Depot GitHub Actions Cache are now scoped by repository. Previously, cache entries saved under a specific key could be read by any other repository in the same GitHub organization. Now, cache entries can only be read by the same repository that saved them.

This ensures that repositories do not have key collisions when using the same cache key, and ensures that one repository cannot unexpectedly read cache entries from another repository of a different trust level, like reading from or writing to a private repository from a public repository.

This change has been deployed to all Depot organizations, and all previous cache entries without an associated repository have been deleted / will be recreated on the next run.