Read the e2e Go version from go.mod and apply the safe go fix modernizers (#4677)

testing/kubectl.go

@@ -122,7 +122,7 @@ func (k *Kubectl) FindPods(ctx context.Context, label string, cfg KubectlConfig)
 	}
 
 	var pods []string
-	for _, l := range strings.Split(out, "\n") {
+	for l := range strings.SplitSeq(out, "\n") {
 		if l != "" {
 			pods = append(pods, l)
 		}

testing/runtime/runtime.go

@@ -26,6 +26,6 @@ func (k Cmdr) CombinedOutput(cmd *exec.Cmd) (string, error) {
 	return string(o), nil
 }
 
-func (k Cmdr) Errorf(f string, args ...interface{}) {
+func (k Cmdr) Errorf(f string, args ...any) {
 	fmt.Fprintf(os.Stderr, f+"\n", args...)
 }