Update Ruby version to 2.7

.github/workflows/test.yaml

@@ -21,7 +21,7 @@ jobs:
       - name: Install Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.3"
+          ruby-version: "2.7"
           bundler-cache: true # runs 'bundle install' and caches installed gems automatically
       - name: Install dependencies
         run: |