test: add a debug container so we can inspect

[rchincha]

No description provided.

[Moosemorals]

Hiya!
Based on the changes, I edited the deployment (kubectl edit -n registry deployments.apps/zot) to include

      - name: busybox
        image: busybox:latest
        command: ["/bin/sh", "-c", "--"]
        args: ["while true; do sleep 30; done;"]
        volumeMounts:
          -  mountPath: "/secret"
             name: "zot-secret"

under spec.template.spec.containers.

I then ran kubectl.exe exec -n registry zot-66fc849cf6-wzdwb -itc busybox -- cat /secret/htpasswd as a proof of concept, and got

user:$2y$05$yE07lhelZYRVpv2OTieb1utN5zloGLgml7Y4gc5gOW.em2M35sVou
k8s:$2y$05$bQHc9W7ZvvJuAda2i24QVul8eeDNa67V.oPWVMTK898FZHL4CpMGW
admin:$2y$05$uMec3ips2C/GZqCSaF/gl.XgoK1.i2zeqGnxV6BvwBXRvy94FUYza

(which matches the heml values.yaml from the main thread).

I'm happy to run diagostics etc, what can I do to help?