Create docker image with release tag automatically

.github/workflows/publish.yml

@@ -0,0 +1,25 @@
+name: Publish Ruby packages
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  notify:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set latest flag for Ruby 3.3
+        if: contains(github.ref, 'v3_3')
+        run: |
+          echo "LATEST=true" >> $GITHUB_ENV
+      - name: Convert tag name to dot from underscore
+        run: |
+            # vX_Y_Z to X.Y.Z
+            echo "RUBY_VERSION=$(echo ${{ github.ref }} | sed 's/v\([0-9]*\)_\([0-9]*\)_\([0-9]*\)/\1.\2.\3/')" >> $GITHUB_ENV
+      - name: Send repository_dispatch
+        run: |
+          curl -X POST \
+            -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
+            -H "Accept: application/vnd.github.everest-preview+json" \
+            https://api.github.com/repos/ruby/docker-images/dispatches \
+            -d '{"event_type": "release", "client_payload": {'ruby_version': ${{ env.RUBY_VERSION }}, 'arch': amd64, 'latest': ${{ env.LATEST }}, 'nopush': false}}'