CORS is broken for HEAD

[SoniEx2]

Steps to reproduce the problem

If attempting to fetch HEAD under some circumstances, server doesn't respond properly.

Expected behaviour

Server should respond roughly the same as "GET + no body"

Actual behaviour

Server does not

Detailed description

Trying to fetch HEAD does not set CORS properly for the ld+json activitystreams content type, but activity+json works. GET works for both.

Specifications

Various instances

[SoniEx2]

As in, this uses GET for maximum compatibility, but it should be able to use HEAD: https://github.com/fedi-to/activitypub-helper/blob/main/protocol-handler.js

But HEAD is broken.