Kapt task fails if @kotlinx.serialization.Serializable is also applied to the class

```
@Entity
@kotlinx.serialization.Serializable
data class User(
    @Id
    val userId: String,
    val name: String
)
```

if I have a class like this, the build fails with the following error: Exception while building entity graph: pl.touk.krush.validation.ElementTypeNotFoundException: Could not resolve Companion type
