bug: mago should report mismatch between `@return` and actual return type

### Description

the provided code crashes at runtime, but mago thinks it's fine because of the `@return` annotation

### Playground Link

https://mago.carthage.software/playground#019b6186-6ed4-ffb8-e3ad-1878cdd6185d

### Reproduction

_No response_

### Environment

playground