Images: Bump Alpine to v3.23.0.

[Gacko]

/triage accepted
/kind cleanup
/priority backlog
/cc @cpanato @strongjz @tao12345666333

[Copilot]

Pull request overview

This PR upgrades the Alpine Linux base image from version 3.22.2 to 3.23.0 across the entire codebase. This is a routine maintenance update to keep base images current with security patches and improvements.

• Updates all direct Alpine image references from alpine:3.22.2 to alpine:3.23.0
• Updates all golang Alpine variant references from alpine3.22 to alpine3.23
• Ensures consistency across Dockerfiles, Makefile, and example documentation

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
test/e2e-image/Dockerfile	Updates Alpine base image for E2E test container
rootfs/Dockerfile-chroot	Updates Alpine base image for chroot variant
images/test-runner/rootfs/Dockerfile	Updates golang Alpine variant for test runner
images/nginx/rootfs/Dockerfile	Updates Alpine base image for both builder and final nginx stages
images/go-grpc-greeter-server/rootfs/Dockerfile	Updates golang Alpine variant for gRPC greeter server
images/fastcgi-helloserver/rootfs/Dockerfile	Updates golang Alpine variant for FastCGI hello server
images/ext-auth-example-authsvc/rootfs/Dockerfile	Updates golang Alpine variant for auth service example
images/custom-error-pages/rootfs/Dockerfile	Updates golang Alpine variant for custom error pages
images/cfssl/rootfs/Dockerfile	Updates Alpine base image for CFSSL tools
docs/examples/customization/sysctl/patch.json	Updates Alpine image reference in sysctl example documentation
Makefile	Updates E2E_IMAGE to use golang with alpine3.23 for build process

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[Gacko]

Requires this to be merged first, since there is no Go v1.25.4 image based on Alpine v3.23.0, but only a Go v1.25.5 one.

[cpanato]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cpanato, Gacko

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[k8s-ci-robot]

New changes are detected. LGTM label has been removed.