chore(deps): bump k8s.io/client-go from 0.27.4 to 0.28.0

Bumps [k8s.io/client-go](https://github.com/kubernetes/client-go) from 0.27.4 to 0.28.0.
- [Changelog](https://github.com/kubernetes/client-go/blob/master/CHANGELOG.md)
- [Commits](https://github.com/kubernetes/client-go/compare/v0.27.4...v0.28.0)

go.mod

@@ -6,8 +6,9 @@ require (
 	github.com/alecthomas/kingpin/v2 v2.3.2
 	github.com/multiplay/go-slack v0.0.0-20200412115802-09e9e2b93fe2
 	github.com/robfig/cron v1.2.0
+	github.com/rogpeppe/go-internal v1.11.0 // indirect
 	github.com/sanity-io/litter v1.5.5
-	k8s.io/api v0.27.4
-	k8s.io/apimachinery v0.27.4
-	k8s.io/client-go v0.27.4
+	k8s.io/api v0.28.0
+	k8s.io/apimachinery v0.28.0
+	k8s.io/client-go v0.28.0
 )