Drop aws-k8s-1.23 settings and plugins

[ginglis13]

Issue number:

Related: #4083

Description of changes:

Follow up from #4227 (comment) to remove aws-k8s-1.23 settings and settings plugins

Also update some docs that refer to k8s-1.23

Testing done:

for variant in aws-k8s-1.24 aws-k8s-1.24-nvidia; do  
  for arch in aarch64 x86_64; do
        cargo make \
                   -e BUILDSYS_ARCH=$arch \
                  -e BUILDSYS_VARIANT=$variant
  done
done

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[koooosh]

LGTM, thanks for the follow-up