Add workflow to run Rubocop action.

git-svn-id: https://svn.redmine.org/redmine/trunk@22813 e93f8b46-1217-0410-a6f0-8f06a7374b81

.github/workflows/rubyonrails.yml

@@ -0,0 +1,17 @@
+name: "Ruby on Rails CI"
+on:
+  push:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Install Ruby and gems
+        uses: ruby/setup-ruby@55283cc23133118229fd3f97f9336ee23a179fcf # v1.146.0
+        with:
+          ruby-version: 3.2
+          bundler-cache: true
+      - name: Lint Ruby files
+        run: bundle exec rubocop --parallel