update k8s.io/code-generator and drop replacement

Author: DockToFuture

internal/tools/go.mod

@@ -338,7 +338,7 @@ require (
 	k8s.io/apiserver v0.35.1 // indirect
 	k8s.io/cli-runtime v0.35.1 // indirect
 	k8s.io/client-go v0.35.1 // indirect
-	k8s.io/code-generator v0.35.1 // indirect
+	k8s.io/code-generator v0.36.0-rc.1 // indirect
 	k8s.io/component-base v0.35.1 // indirect
 	k8s.io/gengo/v2 v2.0.0-20250922181213-ec3ebc5fd46b // indirect
 	k8s.io/klog/v2 v2.140.0 // indirect
@@ -360,9 +360,3 @@ require (
 	sigs.k8s.io/structured-merge-diff/v6 v6.3.2 // indirect
 	sigs.k8s.io/yaml v1.6.0 // indirect
 )
-
-// TODO: get rid of this one once we are done with the upstream issue
-// TODO: a fix until the following upstream issue is clarified.
-//
-// https://github.com/kubernetes/kubernetes/issues/135417
-replace k8s.io/code-generator => github.com/dnaeon/code-generator v0.34.2-fixed-defaulter-gen