Bump k8s.io/apimachinery from 0.19.4 to 0.21.0

Bumps [k8s.io/apimachinery](https://github.com/kubernetes/apimachinery) from 0.19.4 to 0.21.0.
- [Release notes](https://github.com/kubernetes/apimachinery/releases)
- [Commits](kubernetes/apimachinery@v0.19.4...v0.21.0)

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

go.mod

@@ -16,11 +16,9 @@ require (
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.7.0
 	golang.org/x/crypto v0.0.0-20201124201722-c8d3bf9c5392 // indirect
-	golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4 // indirect
-	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c
 	k8s.io/api v0.19.4
-	k8s.io/apimachinery v0.19.4
+	k8s.io/apimachinery v0.21.0
 	k8s.io/cli-runtime v0.19.4
 	k8s.io/client-go v0.19.4
 	sigs.k8s.io/yaml v1.2.0