chi mux mount http.ServMux not working，got 404

```
package main

import (
	"fmt"
	"net/http"

	"github.com/go-chi/chi/v5"
)

func main() {
	root := chi.NewMux()
	mux := http.NewServeMux()
	mux.HandleFunc("GET /world", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintln(w, "hello world")
	})
	root.Mount("/hello", mux)
	http.ListenAndServe(":10011", root)
}
```

got a 404 