humatest compatibility with humago

This is a follow up on #784. The issue raised in the [last comment](https://github.com/danielgtaylor/huma/issues/784#issuecomment-2797713356) appears to persist still, although the main issue was fixed.

Original issue: `huma.WithContext()` causes `humago.Unwrap(ctx)` to panic (resolved).
Followup issue: `huma.WithContext` causes `humago.Unwrap(ctx)` to panic when run through `humatest` (still unresolved).

Although I can understand that `humatest` isn't exactly `humago`, I'm still wondering how can I benefit from `humatest` while doing things like `humago.Unwrap(ctx)` to a `huma.WithContext()`-modified context.