Pingora forwards client-nominated Connection headers to HTTP/1 upstreams, allowing ACL bypass in specific chained deployments

Pingora versions prior to 0.9.0 passed the downstream request through upstreamrequestfilter and wrote it to HTTP/1 upstreams without removing the client's Connection header, other hop-by-hop headers, or the headers Connection nominated, although RFC 9110 Section 7.6.1 requires intermediaries to...