Switch kubectl from docker.io/bitnami/kubectl:latest to docker.io/alpine/k8s:1.32.1

Starting August 28th, Broadcom will no longer release for free the Bitnami Docker images. All existing images will be moved to a new repository (docker.io/bitnamilegacy). They will still be accessible for free but they won't be updated.

We need to find another provider for a kubectl image.

For CD usage, the image absolutely need:

• a shell
• curl or wget

Ideally the image would need:

• to be actively maintained
• a latest tag
• tags for each K8S version
• support for both amd64 and arm64

Kubectl images with high pull count:

image	maintained	latest tag	tags per K8S version	multi-arch
docker.io/kubesphere/kubectl	kind of	✅	some are missing	✅
docker.io/alpine/k8s	✅	❌	✅	✅
docker.io/chainguard/kubectl:latest-dev	✅	✅	❌	✅

❌ Rejected due to missing shell or wget:

image	failing	maintained	latest tag	tags per K8S version	multi-arch
docker.io/rancher/kubectl	no shell	✅	❌	✅	✅
registry.k8s.io/kubectl	no shell	✅	❌	✅	✅
docker.io/giantswarm/kubectl	no wget	✅	❌	✅	❌
docker.io/rapidfort/kubectl-ib	no wget	✅	✅	❌	❌

None is perfect, so for the moment, I suggest we use the same image as in the AWS variant: docker.io/alpine/k8s.

Choosing a better image will be handled in #49.