Don't test Ruby 3.0. Test Ruby 3.1

Author: eduardoj

.github/workflows/rubocop.yml

@@ -13,6 +13,6 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 3.0
+          ruby-version: 3.1
           bundler-cache: true
       - run: bundle exec rake rubocop

.github/workflows/spec.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby: [ '3.0', '3.1', '3.2', 'head' ]
+        ruby: [ '3.1', '3.2', 'head' ]
         rails: [ 'gemfiles/Gemfile.rails-6.1.x', 'gemfiles/Gemfile.rails-7.0.x', 'gemfiles/Gemfile.rails-7.1.x']
         exclude: []
     continue-on-error: ${{ endsWith(matrix.ruby, 'head') || matrix.ruby == 'debug' }}