chore: bump go to 1.18 (#9147)

test/e2e/docker/Dockerfile

@@ -1,7 +1,7 @@
 # We need to build in a Linux environment to support C libraries, e.g. RocksDB.
 # We use Debian instead of Alpine, so that we can use binary database packages
 # instead of spending time compiling them.
-FROM golang:1.15
+FROM golang:1.18
 
 RUN apt-get -qq update -y && apt-get -qq upgrade -y >/dev/null
 RUN apt-get -qq install -y libleveldb-dev librocksdb-dev >/dev/null

test/maverick/node/node.go

@@ -1215,6 +1215,7 @@ func (n *Node) startPrometheusServer(addr string) *http.Server {
 				promhttp.HandlerOpts{MaxRequestsInFlight: n.config.Instrumentation.MaxOpenConnections},
 			),
 		),
+		ReadHeaderTimeout: 10 * time.Second,
 	}
 	go func() {
 		if err := srv.ListenAndServe(); err != http.ErrServerClosed {