Fully dogfood Code Quality by removing homemade docker-in-docker extension

What does this Merge Request do and why?

Fully dogfoods GitLab Code Quality by removing the homemade .docker:use-docker-in-docker extension from Code Quality job on CI as builtin Jobs/Code-Quality.gitlab-ci.yml already has docker-in-docker definition in it.

The residue introduced in !370 (merged) and !458 (merged) was from !1270 (merged).

diff

@@ -1,20 +1,16 @@
 code_quality:
+  stage: test
   image: docker:20.10.12
+  allow_failure: true
   services:
   - name: docker:20.10.12-dind
     command:
     - "--tls=false"
     - "--host=tcp://0.0.0.0:2375"
   variables:
-    DOCKER_VERSION: 20.10.16
-    DOCKER_HOST: tcp://docker:2375
-    DOCKER_TLS_CERTDIR: ''
     DOCKER_DRIVER: overlay2
+    DOCKER_TLS_CERTDIR: ''
     CODE_QUALITY_IMAGE: registry.gitlab.com/gitlab-org/ci-cd/codequality:0.85.26
-  tags:
-  - gitlab-org-docker
-  stage: test
-  allow_failure: true
   needs: []
   script:
   - export SOURCE_CODE=$PWD
@@ -75,6 +71,6 @@
     - Vagrantfile
     - gitlab-openldap/**/*
     - vagrant/assets/**/*
-  extends:
-  - ".docker:use-docker-in-docker"
+  tags:
+  - gitlab-org-docker

before

https://gitlab.com/gitlab-org/gitlab-development-kit/-/ci/editor?branch_name=main&tab=3

code_quality:
  image: docker:20.10.12
  services:
  - name: docker:20.10.12-dind
    command:
    - "--tls=false"
    - "--host=tcp://0.0.0.0:2375"
  variables:
    DOCKER_VERSION: 20.10.16
    DOCKER_HOST: tcp://docker:2375
    DOCKER_TLS_CERTDIR: ''
    DOCKER_DRIVER: overlay2
    CODE_QUALITY_IMAGE: registry.gitlab.com/gitlab-org/ci-cd/codequality:0.85.26
  tags:
  - gitlab-org-docker
  stage: test
  allow_failure: true
  needs: []
  script:
  - export SOURCE_CODE=$PWD
  - |
    if ! docker info &>/dev/null; then
      if [ -z "$DOCKER_HOST" ] && [ -n "$KUBERNETES_PORT" ]; then
        export DOCKER_HOST='tcp://localhost:2375'
      fi
    fi
  - |
    function propagate_env_vars() {
      CURRENT_ENV=$(printenv)

      for VAR_NAME; do
        echo $CURRENT_ENV | grep "${VAR_NAME}=" > /dev/null && echo "--env $VAR_NAME "
      done
    }
  - docker pull --quiet "$CODE_QUALITY_IMAGE"
  - |
    docker run --rm \
      $(propagate_env_vars \
        SOURCE_CODE \
        TIMEOUT_SECONDS \
        CODECLIMATE_DEBUG \
        CODECLIMATE_DEV \
        REPORT_STDOUT \
        REPORT_FORMAT \
        ENGINE_MEMORY_LIMIT_BYTES \
        CODECLIMATE_PREFIX \
      ) \
      --volume "$PWD":/code \
      --volume /var/run/docker.sock:/var/run/docker.sock \
      "$CODE_QUALITY_IMAGE" /code
  artifacts:
    reports:
      codequality:
      - gl-code-quality-report.json
    expire_in: 1 week
  dependencies: []
  rules:
  - changes:
    - "**/*.{rb,erb,sh,yml,example,types}"
    - "{lib,gem,bin}/**/*"
    - "{spec,support}/**/*"
    - ".tool-versions"
    - ".gdkrc"
    - bin/gdk-shell
    - ".gitlab-ci.yml"
    - ".gitlab/ci/**/*"
    - Gemfile{,.lock}
    - Brewfile
    - Makefile
    - Rakefile
    - Dockerfile
    - "**/*/Dockerfile"
    - packages*.txt
    - "**/*/Makefile"
    - Vagrantfile
    - gitlab-openldap/**/*
    - vagrant/assets/**/*
  extends:
  - ".docker:use-docker-in-docker"

after

https://gitlab.com/gitlab-org/gitlab-development-kit/-/ci/editor?branch_name=tnir%2Fuse-code-quality-as-is&tab=3

code_quality:
  stage: test
  image: docker:20.10.12
  allow_failure: true
  services:
  - name: docker:20.10.12-dind
    command:
    - "--tls=false"
    - "--host=tcp://0.0.0.0:2375"
  variables:
    DOCKER_DRIVER: overlay2
    DOCKER_TLS_CERTDIR: ''
    CODE_QUALITY_IMAGE: registry.gitlab.com/gitlab-org/ci-cd/codequality:0.85.26
  needs: []
  script:
  - export SOURCE_CODE=$PWD
  - |
    if ! docker info &>/dev/null; then
      if [ -z "$DOCKER_HOST" ] && [ -n "$KUBERNETES_PORT" ]; then
        export DOCKER_HOST='tcp://localhost:2375'
      fi
    fi
  - |
    function propagate_env_vars() {
      CURRENT_ENV=$(printenv)

      for VAR_NAME; do
        echo $CURRENT_ENV | grep "${VAR_NAME}=" > /dev/null && echo "--env $VAR_NAME "
      done
    }
  - docker pull --quiet "$CODE_QUALITY_IMAGE"
  - |
    docker run --rm \
      $(propagate_env_vars \
        SOURCE_CODE \
        TIMEOUT_SECONDS \
        CODECLIMATE_DEBUG \
        CODECLIMATE_DEV \
        REPORT_STDOUT \
        REPORT_FORMAT \
        ENGINE_MEMORY_LIMIT_BYTES \
        CODECLIMATE_PREFIX \
      ) \
      --volume "$PWD":/code \
      --volume /var/run/docker.sock:/var/run/docker.sock \
      "$CODE_QUALITY_IMAGE" /code
  artifacts:
    reports:
      codequality:
      - gl-code-quality-report.json
    expire_in: 1 week
  dependencies: []
  rules:
  - changes:
    - "**/*.{rb,erb,sh,yml,example,types}"
    - "{lib,gem,bin}/**/*"
    - "{spec,support}/**/*"
    - ".tool-versions"
    - ".gdkrc"
    - bin/gdk-shell
    - ".gitlab-ci.yml"
    - ".gitlab/ci/**/*"
    - Gemfile{,.lock}
    - Brewfile
    - Makefile
    - Rakefile
    - Dockerfile
    - "**/*/Dockerfile"
    - packages*.txt
    - "**/*/Makefile"
    - Vagrantfile
    - gitlab-openldap/**/*
    - vagrant/assets/**/*
  tags:
  - gitlab-org-docker

Follows up !1270 (merged)

Updates !2038 (merged) (, !2036 (merged)), and !1229 (merged)

Merge Request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• [n/a] Tests added for new functionality. If not, please raise Issue to follow-up.
• [n/a] Documentation added/updated, if needed.
• [n/a] gdk doctor test added, if needed.
• [n/a] Add the ~highlight label if this MR should be included in the CHANGELOG.md.