Classifies one REST probe response. REST is not enabled when nothing answers the path (404) or
when the GraphQL route answered it: with GraphQL at the root path, a REST URL that nothing
mounted falls through to Apollo, which refuses it with a 400. Any other refusal comes from REST
itself, which may not honour a freshly minted key yet, so it is retried.
Classifies one REST probe response. REST is not enabled when nothing answers the path (404) or when the GraphQL route answered it: with GraphQL at the root path, a REST URL that nothing mounted falls through to Apollo, which refuses it with a 400. Any other refusal comes from REST itself, which may not honour a freshly minted key yet, so it is retried.