fix(turbo-tasks): Remove `T: Serialize` bound from ResolveVc (#69995)
With the default derived implementation, serde would inject a `T: Serialize` or `T: Deserialize` bound.
However, like `Vc`, `ResolvedVc` is serialized as a couple numeric IDs (the type of `T` doesn't matter), so we shouldn't have this restriction on `ResolvedVc`.
Also, clean up `Vc<T>` using the same `bound = ""` trick with the derive macro.