Stale reads on ListWorkerVersions and ListUserWorkerRuns

https://redmine.teklia.com/issues/5960

Creating a new worker version in the frontend does refresh the worker versions list immediately, but the list does not change in prod because the new version has not been replicated yet. The same thing happens when creating a new user worker run.

Both endpoints are not among the ones where we care about very high performance, unlike those for ML results for example, so we can put some good old .using('default') here.