all: use Go 1.22 range-over-int

Updates #11058

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

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