utils/mtls: annotate false positive gosec warning

The warning from gosec is a false positive because of the
usage of the InsecureSkipVerify flag, which is only set to
false for tests.

pkg/utils/mtls.go

@@ -28,6 +28,7 @@ func setupMutualTLS(insecure bool, serverName string, certPem []byte, keyPem []b
 		return nil, errors.Errorf("[grpc][mTLS][%s] Failed to append client certs", serverName)
 	}
 
+	// #nosec G402
 	tlsConfig := tls.Config{
 		InsecureSkipVerify: insecure,
 		ServerName:         serverName,