Upgrade to debian 12 bookworm

[jmhbnz]

What would you like to be added?

Debian 12 "bookworm" was released in June 2023. We should consider updating etcd project from debian 11 "bullseye".

The Kubernetes project has already made a start on this, refer: kubernetes/release#3128.

For us this would involve:

• Updating the container: used in .github/workflows/ files.

-    container: golang:1.20-bullseye
+    container: golang:1.20-bookworm

• Updating the .devcontainer/devcontainer.json used for etcd container based development environments.

-       "image": "mcr.microsoft.com/devcontainers/go:1.20-bullseye",
+       "image": "mcr.microsoft.com/devcontainers/go:1.20-bookworm",

• Update the FROM: base image in our Dockerfile.

-FROM --platform=linux/${ARCH} gcr.io/distroless/static-debian11
+FROM --platform=linux/${ARCH} gcr.io/distroless/static-debian12

Why is this needed?

Ensure etcd releases, testing workflows and container based development use a modern base image.

Avoid any potential future technical debt and uncover any potential issues early.

[jmhbnz]

The initial work for this has now been completed in #16516.

@ahrtr, @serathius what are your thoughts on backporting this? My thinking is we would only do so if for some reason bullseye was broken or out of support. Keen to double check before I close this though.

[jmhbnz]

Closing as the initial pr is complete and my instinct is we shouldn't backport this change.

Happy to re-open if my assessment isn't right 🙏🏻