Bump k8s.io/code-generator from 0.25.7 to 0.25.8

Bumps [k8s.io/code-generator](https://github.com/kubernetes/code-generator) from 0.25.7 to 0.25.8.
- [Release notes](https://github.com/kubernetes/code-generator/releases)
- [Commits](kubernetes/code-generator@v0.25.7...v0.25.8)

---
updated-dependencies:
- dependency-name: k8s.io/code-generator
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

go.mod

@@ -31,7 +31,7 @@ require (
 	k8s.io/api v0.25.8
 	k8s.io/apimachinery v0.25.8
 	k8s.io/client-go v0.25.7
-	k8s.io/code-generator v0.25.7
+	k8s.io/code-generator v0.25.8
 	k8s.io/klog v1.0.0
 	k8s.io/kube-openapi v0.0.0-20221012153701-172d655c2280
 	knative.dev/pkg v0.0.0-20230221145627-8efb3485adcf