[ENH] - Implement refresh_user to refresh JupyterHub scopes permissions

[aktech]

Feature description

Ref: https://jupyterhub.readthedocs.io/en/stable/reference/api/auth.html#jupyterhub.auth.Authenticator.refresh_user

After https://github.com/nebari-dev/nebari/pull/2471 is merged, we will have keycloak role's scopes parsing available. The fetches the scopes for users on every login, it would be great to refresh user more frequently than login.

Value and/or benefit

• To ensure auth state is up-to-date with upstream prior to spawn to avoid stale auth info.

Anything else?

No response