Upgrade kube dependencies and snapshotter client kube deps to v0.25.2

vendor/github.com/kubernetes-csi/external-snapshotter/client/v6/clientset/versioned/clientset.go

@@ -61,6 +61,10 @@ func (c *Clientset) Discovery() discovery.DiscoveryInterface {
 func NewForConfig(c *rest.Config) (*Clientset, error) {
 	configShallowCopy := *c
 
+	if configShallowCopy.UserAgent == "" {
+		configShallowCopy.UserAgent = rest.DefaultKubernetesUserAgent()
+	}
+
 	// share the transport between all clients
 	httpClient, err := rest.HTTPClientFor(&configShallowCopy)
 	if err != nil {