Move the CNG triggering to a dedicated job in the `test` stage

What does this MR do?

This is to save between 5 and 16 minutes upon retries of the review-deploy job, see https://gitlab.com/gitlab-org/gitlab-ce/issues/56538#note_133412287.

What are the relevant issue numbers?

Closes #56660 (closed).

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer

.gitlab-ci.yml

@@ -947,6 +947,20 @@ no_ee_check:
     - //@gitlab-org/gitlab-ce
 
 # GitLab Review apps
+review-build-cng:
+  <<: *single-script-job
+  variables:
+    <<: *single-script-job-variables
+    SCRIPT_NAME: trigger-build
+  script:
+    - gem install gitlab --no-document
+    - apk add --update openssl curl jq
+    - wget $CI_PROJECT_URL/raw/$CI_COMMIT_SHA/scripts/review_apps/review-apps.sh
+    - chmod 755 review-apps.sh
+    - source ./review-apps.sh
+    - wait_for_job_to_be_done "gitlab:assets:compile"
+    - BUILD_TRIGGER_TOKEN=$REVIEW_APPS_BUILD_TRIGGER_TOKEN ./$SCRIPT_NAME cng
+
 review-deploy:
   <<: *review-base
   retry: 2
@@ -961,15 +975,14 @@ review-deploy:
     <<: *review-environment
     on_stop: review-stop
   before_script:
-    - apk update && apk add jq
-    - gem install gitlab --no-document
-  script:
     - export GITLAB_SHELL_VERSION=$(<GITLAB_SHELL_VERSION)
     - export GITALY_VERSION=$(<GITALY_SERVER_VERSION)
     - export GITLAB_WORKHORSE_VERSION=$(<GITLAB_WORKHORSE_VERSION)
+    - apk update && apk add jq
+    - gem install gitlab --no-document
     - source ./scripts/review_apps/review-apps.sh
-    - wait_for_job_to_be_done "gitlab:assets:compile"
-    - BUILD_TRIGGER_TOKEN=$REVIEW_APPS_BUILD_TRIGGER_TOKEN ./scripts/trigger-build cng
+  script:
+    - wait_for_job_to_be_done "review-build-cng"
     - check_kube_domain
     - download_gitlab_chart
     - ensure_namespace
@@ -980,7 +993,6 @@ review-deploy:
 
 .review-qa-base: &review-qa-base
   <<: *review-docker
-  retry: 2
   allow_failure: true
   variables:
     <<: *review-docker-variables