Don't return a `Proxy` if `->withoutPersist()` was used

[nikophil]

this is a big BC, but we should at least think how this could be deprecated

[kbond]

I'm thinking we'd wrap this up in the deprecation of the Proxy object entirely. Once we use real proxies, we'd return an instance of the real object

[nikophil]

ok then, let's close this