Update chi/middleware to chi/v5/middleware (#17888)

Fix #17880


Co-authored-by: Lauris BH <lauris@nix.lv>

vendor/github.com/go-chi/chi/v5/middleware/heartbeat.go

@@ -0,0 +1,26 @@
+package middleware
+
+import (
+	"net/http"
+	"strings"
+)
+
+// Heartbeat endpoint middleware useful to setting up a path like
+// `/ping` that load balancers or uptime testing external services
+// can make a request before hitting any routes. It's also convenient
+// to place this above ACL middlewares as well.
+func Heartbeat(endpoint string) func(http.Handler) http.Handler {
+	f := func(h http.Handler) http.Handler {
+		fn := func(w http.ResponseWriter, r *http.Request) {
+			if r.Method == "GET" && strings.EqualFold(r.URL.Path, endpoint) {
+				w.Header().Set("Content-Type", "text/plain")
+				w.WriteHeader(http.StatusOK)
+				w.Write([]byte("."))
+				return
+			}
+			h.ServeHTTP(w, r)
+		}
+		return http.HandlerFunc(fn)
+	}
+	return f
+}