all: use Go 1.22 range-over-int

Updates #11058

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

tstest/clock_test.go

@@ -153,7 +153,7 @@ func TestZeroInitClock(t *testing.T) {
 		t.Errorf("clock has step %v, want 0", step)
 	}
 
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		if got := clock.Now(); !got.Equal(start) {
 			t.Errorf("step %v: clock.Now() = %v, want %v", i, got, start)
 		}

tstest/integration/vms/vm_setup_test.go

@@ -50,7 +50,7 @@ func (vm *vmInstance) running() bool {
 
 func (vm *vmInstance) waitStartup(t *testing.T) {
 	t.Helper()
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		if vm.running() {
 			break
 		}

tstest/integration/vms/vms_steps_test.go

@@ -23,7 +23,7 @@ func retry(t *testing.T, fn func() error) {
 	t.Helper()
 	const tries = 3
 	var err error
-	for i := 0; i < tries; i++ {
+	for i := range tries {
 		err = fn()
 		if err != nil {
 			t.Logf("%dth invocation failed, trying again: %v", i, err)

tstest/integration/vms/vms_test.go

@@ -321,7 +321,7 @@ func (h *Harness) setupSSHShell(t *testing.T, d Distro, ipm ipMapping) (*ssh.Cli
 	// don't use socket activation.
 	const maxRetries = 5
 	var working bool
-	for i := 0; i < maxRetries; i++ {
+	for range maxRetries {
 		cli, err := ssh.Dial("tcp", hostport, ccfg)
 		if err == nil {
 			working = true

tstest/natlab/natlab_test.go

@@ -17,7 +17,7 @@ import (
 func TestAllocIPs(t *testing.T) {
 	n := NewInternet()
 	saw := map[netip.Addr]bool{}
-	for i := 0; i < 255; i++ {
+	for range 255 {
 		for _, f := range []func(*Interface) netip.Addr{n.allocIPv4, n.allocIPv6} {
 			ip := f(nil)
 			if saw[ip] {

tstest/resource.go

@@ -33,7 +33,7 @@ func ResourceCheck(tb testing.TB) {
 			return
 		}
 		// Goroutines might be still exiting.
-		for i := 0; i < 300; i++ {
+		for range 300 {
 			if runtime.NumGoroutine() <= startN {
 				return
 			}