all: modernize (#5498)

* modernize string cut usage

* modernize string cut prefix usage

* modernize slices helper usage

* modernize min and max usage

* modernize loop variable copies

* modernize integer range loops

* modernize map copy loops

* modernize go types iterator usage

* modernize empty interface usage

* modernize atomic type usage

* modernize string builders

* modernize string split iteration

* modernize remaining loop variable copies

* modernize usb cdc min usage

* modernize src integer range loops

* modernize example empty interface usage

* modernize src min and max usage

* modernize src integer range loops

* modernize src empty interface usage

* modernize src atomic type usage

* modernize reflect type lookups

* modernize review nits

src/examples/memstats/memstats.go

@@ -25,7 +25,7 @@ func main() {
 func escapesToHeap() {
 	n := rand.Intn(100)
 	println("Doing ", n, " iterations")
-	for i := 0; i < n; i++ {
+	for i := range n {
 		s := make([]byte, i)
 		_ = append(s, 42)
 	}

src/examples/test/test.go

@@ -70,7 +70,7 @@ func main() {
 	printItf(Number(3))
 	s := Stringer(thing)
 	println("Stringer.String():", s.String())
-	var itf interface{} = s
+	var itf any = s
 	println("Stringer.(*Thing).String():", itf.(Stringer).String())
 
 	// unusual calls
@@ -124,7 +124,7 @@ func strlen(s string) int {
 	return len(s)
 }
 
-func printItf(val interface{}) {
+func printItf(val any) {
 	switch val := val.(type) {
 	case Doubler:
 		println("is Doubler:", val.Double())