Update auto-build-image to v0.6.0

This is a routine update of the underlying software:

- Updates pack to v0.18.0
- Updates docker to v20.10.6

changelogs/unreleased/update-auto-build-image-to-0-6-0.yml

+---
+title: Update auto-build-image to v0.6.0, updating the included docker to 20.10.6 and pack to 0.18.0
+merge_request: 59525
+author:
+type: changed

lib/gitlab/ci/templates/Jobs/Build.gitlab-ci.yml

 build:
   stage: build
-  image: "registry.gitlab.com/gitlab-org/cluster-integration/auto-build-image:v0.4.0"
+  image: "registry.gitlab.com/gitlab-org/cluster-integration/auto-build-image:v0.6.0"
   variables:
     DOCKER_TLS_CERTDIR: ""
   services:
-    - docker:19.03.12-dind
+    - docker:20.10.6-dind
   script:
     - |
       if [[ -z "$CI_COMMIT_TAG" ]]; then