[PATCH] sendf: ignore response body to HEAD

[PATCH] sendf: ignore response body to HEAD

and mark the stream for close, but return OK since the response this far
was ok - if headers were received. Partly because this is what curl has
done traditionally.

Test 499 verifies. Updates test 689.

Reported-by: Sergey Bronnikov
Bug: https://curl.se/mail/lib-2024-02/0000.html
Closes #12842

Gbp-Pq: Name sendf_ignore_response_body_to_head.patch