Exclude middleware/profiler.go in TinyGo, as there's no net/http/pprof pkg

[cxjava]

when I want to use middleware in tinygo, it will failed because of https://github.com/go-chi/chi/blob/master/middleware/profiler.go, there is no package net/http/pprof for tinygo.

	r := chi.NewRouter()
	r.Use(middleware.CleanPath)
	r.Use(middleware.RealIP)
	r.Use(middleware.Logger)
	r.Use(middleware.Recoverer)

error output:

../../../go/pkg/mod/github.com/go-chi/chi/[email protected]/middleware/profiler.go:6:2: 
package net/http/pprof is not in std (/Users/user/Library/Caches/tinygo/goroot-598d56643c1f2b0a17cb7ed7f5003addae1fc3ee5af904a1c5356bb7118a4988/src/net/http/pprof)

we need to exclude middleware/profiler.go when use tinygo.

[VojtechVitek]

Follow-up for #978. Thanks!

LGTM