Replace Zio and Futures workarounds with proper lib methods once merged

[carlosedp]

Replace the code and helpers from c9b67f4 once the PRs below from quarkus-scala3 extension gets merged:

• Support for ZIO as return type in Rest Resources quarkiverse/quarkus-scala3#52
• Future[T] and Promise[T] as Controller ReturnTypes quarkiverse/quarkus-scala3#51