Update k8s dependency version to 1.21

Signed-off-by: xinyanwu409 <wxinyan@vmware>

vendor/golang.org/x/sys/unix/ptrace_ios.go

@@ -0,0 +1,12 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build ios
+// +build ios
+
+package unix
+
+func ptrace(request int, pid int, addr uintptr, data uintptr) (err error) {
+	return ENOTSUP
+}