[7.17](backport #16148) Add details on decommissioning of soak testing infra

[mergify]

Add status of the long-running soak test cluster.

Motivation/summary

Check #14411

Checklist

- [ ] Update CHANGELOG.asciidoc

• Documentation has been updated

How to test these changes

N/A

Related issues

Closes #14411

---

This is an automatic backport of pull request #16148 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of f6e526f has failed:

On branch mergify/bp/7.17/pr-16148
Your branch is up to date with 'origin/7.17'.

You are currently cherry-picking commit f6e526f9.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   testing/apmsoak/README.md

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[lahsivjar]

Wrong PR, this is not for 7.x. Closing.