cleanup: delete rand.Seed(time.Now().UnixNano()) and using global number generator.

see https://tip.golang.org/doc/go1.20

Signed-off-by: Lan Liang <gcslyp@gmail.com>

test/integration/volume/main_test.go

@@ -17,14 +17,11 @@ limitations under the License.
 package volume
 
 import (
-	"math/rand"
 	"testing"
-	"time"
 
 	"k8s.io/kubernetes/test/integration/framework"
 )
 
 func TestMain(m *testing.M) {
-	rand.Seed(time.Now().UnixNano())
 	framework.EtcdMain(m.Run)
 }