Bump k8s.io/apimachinery from 0.19.4 to 0.20.0

Bumps [k8s.io/apimachinery](https://github.com/kubernetes/apimachinery) from 0.19.4 to 0.20.0.
- [Release notes](https://github.com/kubernetes/apimachinery/releases)
- [Commits](https://github.com/kubernetes/apimachinery/compare/v0.19.4...v0.20.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/golang.org/x/net/html/const.go

@@ -52,7 +52,7 @@ var isSpecialElementMap = map[string]bool{
 	"iframe":     true,
 	"img":        true,
 	"input":      true,
-	"keygen":     true,
+	"keygen":     true, // "keygen" has been removed from the spec, but are kept here for backwards compatibility.
 	"li":         true,
 	"link":       true,
 	"listing":    true,