Fix incorrect format for CI with multiple Rubys

Author: peerkleio

.github/workflows/ci.yml

@@ -18,14 +18,15 @@ jobs:
           - Gemfile.rails-6.0-stable
           - Gemfile.rails-6.1-stable
           - Gemfile.rails-7.0-stable
+        ruby-version: ['3.1', '3.0', '2.7']
     env:
       BUNDLE_GEMFILE: gemfiles/${{ matrix.gemfile }}
     steps:
       - uses: actions/checkout@v3
-      - name: Set up Ruby
+      - name: Set up Ruby ${{ matrix.ruby-version }}
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: ["2.7", "3.0", "3.1"]
+          ruby-version: ${{ matrix.ruby-version }}
       - name: Install dependencies
         run: bundle install
       - name: Run tests