chi.Walk missing middlewares #750

Hi,

I was trying to use chi.Walk to get a report of all routes and the middlewares used by every route. I noticed that some of the middlewares were missing from some of the nested routes when using groups.

Example routes:

	r := chi.NewRouter()

	r.Use(middleware.RequestID)

	r.Get("/A", func(w http.ResponseWriter, r *http.Request) {})

	r.Group(func(r chi.Router) {
		r.Use(middleware.Timeout(2500 * time.Millisecond))

		r.Get("/B", func(w http.ResponseWriter, r *http.Request) {})

		r.Route("/C", func(r chi.Router) {

			// Walk on the below route does not show the Timeout middleware
			r.Get("/D", func(w http.ResponseWriter, r *http.Request) {})
		})
	})

In the example above, I expected the C/D route to have both RequestId and Timeout middlewares. but chi.Walk only shows RequestID.

It's possible I'm missing something here and this is behaving as expected.

Go playground link: https://go.dev/play/p/HKh7cA35Bgx