build(deps): bump k8s.io/client-go from 0.19.4 to 0.20.0 (#4334)

Bumps [k8s.io/client-go](https://github.com/kubernetes/client-go) from 0.19.4 to 0.20.0.
- [Release notes](https://github.com/kubernetes/client-go/releases)
- [Changelog](https://github.com/kubernetes/client-go/blob/master/CHANGELOG.md)
- [Commits](https://github.com/kubernetes/client-go/compare/v0.19.4...v0.20.0)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

go.mod

@@ -36,8 +36,8 @@ require (
 	google.golang.org/api v0.29.0
 	google.golang.org/grpc v1.29.1
 	gopkg.in/DataDog/dd-trace-go.v1 v1.27.1
-	k8s.io/api v0.19.4
+	k8s.io/api v0.20.0
 	k8s.io/apimachinery v0.20.0
-	k8s.io/client-go v0.19.4
+	k8s.io/client-go v0.20.0
 	k8s.io/klog v1.0.0
 )