chore(deps): Bump k8s.io/apiextensions-apiserver from 0.20.4 to 0.21.0

Bumps [k8s.io/apiextensions-apiserver](https://github.com/kubernetes/apiextensions-apiserver) from 0.20.4 to 0.21.0.
- [Release notes](https://github.com/kubernetes/apiextensions-apiserver/releases)
- [Commits](https://github.com/kubernetes/apiextensions-apiserver/compare/v0.20.4...v0.21.0

)
Signed-off-by: dependabot[bot] <support@github.com>

go.mod

@@ -35,14 +35,14 @@ require (
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.7.0
 	github.com/xeipuuv/gojsonschema v1.2.0
-	golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad
-	golang.org/x/term v0.0.0-20201117132131-f5c789dd3221
-	k8s.io/api v0.20.4
-	k8s.io/apiextensions-apiserver v0.20.4
-	k8s.io/apimachinery v0.20.4
-	k8s.io/apiserver v0.20.4
+	golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83
+	golang.org/x/term v0.0.0-20210220032956-6a3ed077a48d
+	k8s.io/api v0.21.0
+	k8s.io/apiextensions-apiserver v0.21.0
+	k8s.io/apimachinery v0.21.0
+	k8s.io/apiserver v0.21.0
 	k8s.io/cli-runtime v0.20.4
-	k8s.io/client-go v0.20.4
+	k8s.io/client-go v0.21.0
 	k8s.io/klog/v2 v2.8.0
 	k8s.io/kubectl v0.20.4
 	sigs.k8s.io/yaml v1.2.0