A request with neither Content-Length nor chunked Transfer-Encoding
has no body (RFC 9112 6.3), and builds with TLS support read none.
Builds without it still read whatever followed such a request on a
connection about to close, up to EOF, as its body. Every build now
reads no body. Tests that exercised only that read, or passed whatever
the server did, are removed, and a new one checks in every build that
the bytes after such a request are not taken as its body.