Values of type 'Any' can be converted to everything

The following code compiles, but I'm not confident it should:
```scala
def exVeritateQuodlibet[A](a: Any): A = a match {}
```

This is likely an artefact of #1219.

---

If I had to guess, it's an interplay between the Core generation for an empty match
https://github.com/effekt-lang/effekt/blob/34bbb3e7855d4ce0a7c0c985394805d8a025f275/effekt/shared/src/main/scala/effekt/core/Transformer.scala#L381-L385

and `Any` being declared as an empty type
https://github.com/effekt-lang/effekt/blob/34bbb3e7855d4ce0a7c0c985394805d8a025f275/effekt/shared/src/main/scala/effekt/symbols/builtins.scala#L44-L45

Start by compiling the example, then inspect the empty-match Core generation in effekt/shared/src/main/scala/effekt/core/Transformer.scala and the Any declaration in effekt/shared/src/main/scala/effekt/symbols/builtins.scala. Determine whether the conversion is intended and document the resulting behavior with regression coverage.

Written by the indexing model from the issue text.