all: use Go 1.22 range-over-int

Updates #11058

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

types/lazy/sync_test.go

@@ -89,7 +89,7 @@ func TestSyncValueConcurrent(t *testing.T) {
 		routines = 10000
 	)
 	wg.Add(routines)
-	for i := 0; i < routines; i++ {
+	for range routines {
 		go func() {
 			defer wg.Done()
 			// Every goroutine waits for the go signal, so that more of them