Run modernize (#21546)

`go run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest -fix -test ./...` executed.

`go generate ./...` ran afterwards to keep generated.

cmd/tier_test.go

@@ -27,10 +27,10 @@ func TestTierMetrics(t *testing.T) {
 	globalTierMetrics.Observe(tier, 200*time.Millisecond)
 	expSuccess := 10
 	expFailure := 5
-	for i := 0; i < expSuccess; i++ {
+	for range expSuccess {
 		globalTierMetrics.logSuccess(tier)
 	}
-	for i := 0; i < expFailure; i++ {
+	for range expFailure {
 		globalTierMetrics.logFailure(tier)
 	}
 	metrics := globalTierMetrics.Report()