Update to the newest inkwell version

[ghaith]

Inkwell is now on version 0.4
There are a lot of changes to the API, the builder methods all return results now.
We should start considering an update. I believe we would need to introduce thiserror for the codegen or find a way to convert the errors directly into diagnostics.
I'd suggest we plan this after the diagnostics are done so we base on the work there.