Don't refresh the token on spawn

This call is expensive and users most probably have a new token already.
It has been enabled since OAuthenticator️ v16.0.0

swan-cern/values.yaml

@@ -148,10 +148,10 @@ swan:
           client_id: # placeholder, check secrets
           client_secret: # placeholder, check secrets
           oauth_callback_url: # placeholder, check secrets
-
           # skip refreshing tokens if already refreshed in last 110 minutes
           # this assumes tokens provided by keycloak are valid for 120 minutes
           auth_refresh_age: 6600
+          refresh_pre_spawn: false
         JupyterHub:
           allow_named_servers: False
         SwanKubeSpawner: