Add GitHub Actions workflow to notify Zulip on release

Author: jimboid

.github/workflows/zulip-notify.yaml

@@ -0,0 +1,33 @@
+name: Notify Zulip
+ 
+on:
+  release:
+    types: [released]
+
+jobs:
+  notify:
+    runs-on: ubuntu-24.04
+    steps:
+      - name: Post announcement to Zulip
+        env:
+          ZULIP_BOT_EMAIL: ${{ secrets.ZULIP_BOT_EMAIL }}
+          ZULIP_BOT_API_KEY: ${{ secrets.ZULIP_BOT_API_KEY }}
+          ZULIP_SITE: ${{ secrets.ZULIP_SITE }}
+          REPO: ${{ github.event.repository.name }}
+          TAG: ${{ github.event.release.tag_name }}
+          RELEASE_URL: ${{ github.event.release.html_url }}
+          CHANGELOG: ${{ github.event.release.body }}
+        run: |
+          CONTENT=$(cat <<EOF
+          **${REPO}** [${TAG}](${RELEASE_URL}) has been released 🎉
+
+          ${CHANGELOG}
+          EOF
+          )
+
+          curl -sSf "${ZULIP_SITE}/api/v1/messages" \
+            -u "${ZULIP_BOT_EMAIL}:${ZULIP_BOT_API_KEY}" \
+            --data-urlencode type=stream \
+            --data-urlencode "to=announcements" \
+            --data-urlencode "topic=releases" \
+            --data-urlencode "content=${CONTENT}"