go.mod: drop redundant excludes (#10557)

go.mod

@@ -268,29 +268,3 @@ require (
 )
 
 replace github.com/imdario/mergo => github.com/imdario/mergo v0.3.16
-
-exclude (
-	// Exclude pre-go-mod kubernetes tags, because they are older
-	// than v0.x releases but are picked when updating dependencies.
-	k8s.io/client-go v1.4.0
-	k8s.io/client-go v1.5.0
-	k8s.io/client-go v1.5.1
-	k8s.io/client-go v1.5.2
-	k8s.io/client-go v2.0.0-alpha.1+incompatible
-	k8s.io/client-go v2.0.0+incompatible
-	k8s.io/client-go v3.0.0-beta.0+incompatible
-	k8s.io/client-go v3.0.0+incompatible
-	k8s.io/client-go v4.0.0-beta.0+incompatible
-	k8s.io/client-go v4.0.0+incompatible
-	k8s.io/client-go v5.0.0+incompatible
-	k8s.io/client-go v5.0.1+incompatible
-	k8s.io/client-go v6.0.0+incompatible
-	k8s.io/client-go v7.0.0+incompatible
-	k8s.io/client-go v8.0.0+incompatible
-	k8s.io/client-go v9.0.0-invalid+incompatible
-	k8s.io/client-go v9.0.0+incompatible
-	k8s.io/client-go v10.0.0+incompatible
-	k8s.io/client-go v11.0.0+incompatible
-	k8s.io/client-go v11.0.1-0.20190409021438-1a26190bd76a+incompatible
-	k8s.io/client-go v12.0.0+incompatible
-)