all: use Go 1.22 range-over-int

Updates #11058

Change-Id: I35e7ef9b90e83cac04ca93fd964ad00ed5b48430
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

types/netmap/netmap.go

@@ -137,7 +137,7 @@ func (nm *NetworkMap) PeerByTailscaleIP(ip netip.Addr) (peer tailcfg.NodeView, o
 	}
 	for _, n := range nm.Peers {
 		ad := n.Addresses()
-		for i := 0; i < ad.Len(); i++ {
+		for i := range ad.Len() {
 			a := ad.At(i)
 			if a.Addr() == ip {
 				return n, true

types/netmap/nodemut.go

@@ -73,7 +73,7 @@ func (m NodeMutationLastSeen) Apply(n *tailcfg.Node) {
 var peerChangeFields = sync.OnceValue(func() []reflect.StructField {
 	var fields []reflect.StructField
 	rt := reflect.TypeFor[tailcfg.PeerChange]()
-	for i := 0; i < rt.NumField(); i++ {
+	for i := range rt.NumField() {
 		fields = append(fields, rt.Field(i))
 	}
 	return fields

types/netmap/nodemut_test.go

@@ -44,7 +44,7 @@ func TestMapResponseContainsNonPatchFields(t *testing.T) {
 	}
 
 	rt := reflect.TypeFor[tailcfg.MapResponse]()
-	for i := 0; i < rt.NumField(); i++ {
+	for i := range rt.NumField() {
 		f := rt.Field(i)
 
 		var want bool