ci: add tag only flow for releases

Release.gitlab-ci.yml

@@ -190,4 +190,33 @@ release:
     when: never
   - if: $CI_DEFAULT_BRANCH != $CI_COMMIT_BRANCH
     when: never
+  - if: $UNBOUND_RELEASE_TAG_ONLY == "true"
+    when: never
+  - if: '$CI_COMMIT_TITLE =~ /^chore\(release\): prepare for .*$/'
+
+tag:
+  stage: .pre
+  image: alpine:latest
+  needs:
+  - prepare_release
+  before_script:
+  - 'apk add --no-cache curl'
+  script:
+  - |
+    echo "Creating tag"
+    NAME="$(cat VERSION)"
+    MESSAGE="$(cat CHANGES.md)"
+    curl -sf -X POST \
+      -H "Authorization: Bearer ${UNBOUND_RELEASE_TOKEN}" \
+      -H "Content-Type: application/json" \
+        "https://gitlab.com/api/v4/projects/${CI_PROJECT_ID}/repository/tags?tag_name=${NAME}&ref=${CI_DEFAULT_BRANCH}&message=${NAME}"
+  rules:
+  - if: $UNBOUND_RELEASE_TOKEN == null
+    when: never
+  - if: $CI_DEFAULT_BRANCH != $CI_COMMIT_BRANCH
+    when: never
+  - if: $UNBOUND_RELEASE_TAG_ONLY == null
+    when: never
+  - if: $UNBOUND_RELEASE_TAG_ONLY == "false"
+    when: never
   - if: '$CI_COMMIT_TITLE =~ /^chore\(release\): prepare for .*$/'