Set ruby-version in workflow file

.github/workflows/rspec.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ruby/setup-ruby@v1
         with:
-          # The Ruby version is determined by either a `.ruby-version` or a `.tool-versions` file in root of the repo.
+          ruby-version: '3.3'
           bundler-cache: true
       - name: Run a11y tests
         run: |