In general, when looking for the up-to-date recommendation you should check the quickstarts instead of going straight to GitHub repositories as the repositories themselves may linger beyond their initial usage as they are public and it would make sense to remove them.
For Go you would have the following quickstarts:
- Web application: Auth0 Go SDK Quickstarts: Login
- Backend/API: Auth0 Go API SDK Quickstarts: Authorization
Looking at the quickstarts in particular the API one you will notice that auth0-community/go-auth0 in indeed one of the dependencies being used so it indicates that this is the recommendation for that scenario.