build: update client-go and other kube dependencies to 1.20.6

client-go 1.20.6 has a fix for below CVE: This patch address this
via updating client-go and other dependencies.

CVE-2019-11250 : The MITRE CVE dictionary describes this issue as:

The Kubernetes client-go library logs request headers at verbosity
levels of 7 or higher. This can disclose credentials to unauthorized
users via logs or command output. Kubernetes components (such as
kube-apiserver) prior to v1.16.0, which make use of basic or bearer
token authentication, and run at high verbosity levels, are affected.

Ref# https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-11250

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

vendor/sigs.k8s.io/apiserver-network-proxy/konnectivity-client/pkg/client/client.go

@@ -115,6 +115,12 @@ func (t *grpcTunnel) serve(c clientConn) {
 					connid: resp.ConnectID,
 				}
 			}
+
+			if resp.Error != "" {
+				// On dial error, avoid leaking serve goroutine.
+				return
+			}
+
 		case client.PacketType_DATA:
 			resp := pkt.GetData()
 			// TODO: flow control