GitHub API - Actions Storage

There’s no place in the GitHub API (either REST or GraphQL) where the storage used by GitHub Actions workflows is identified, that I can find – am I missing it? It’s shown in the billing reports, but I can’t find any evidence of it in the API currently.

I’d be happy to include it into my actions usage extension for the gh cli, but I can’t find it in the API Docs or in Google searches, but figured there’s no harm in asking you nice folks.