[9.20] new: ci: Prepare release announcement MR

In the 'release' stage, create an MR automatically with the
corresponding release announcement. The input for this is taken from
metadata.json in bind9-qa.

Backport of MR !11039

Merge branch 'backport-andoni/release-announcement-preparation-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!11040

.gitlab-ci.yml

@@ -1802,6 +1802,26 @@ sign:
   when: manual
   allow_failure: false
 
+# Job creating the release announcement MR in Printing Press
+
+prepare-release-announcement:
+  <<: *base_image
+  stage: release
+  when: manual
+  variables:
+    GIT_DEPTH: 1
+  before_script:
+    - git clone --depth 1 https://gitlab.isc.org/isc-projects/bind9-qa.git
+  script:
+    - bind9-qa/releng/prepare_release_announcement.py --metadata bind9-qa/releng/metadata.json
+  needs: []
+  rules:
+    - if: '$CI_COMMIT_TAG != null && $CI_COMMIT_TAG !~ /-S/'
+  artifacts:
+    paths:
+      - printing-press/
+    when: on_failure
+
 # Job merging the tag back into its base branch
 
 merge-tag: