Merge pull request #5 from wuest/slim-down-ci

Remove EOL ruby, run rubocop only once

.github/workflows/ci.yaml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       matrix:
         os: [ 'ubuntu-20.04', 'ubuntu-22.04' ]
-        ruby-version: ['3.0', '3.1', '3.2', '3.3']
+        ruby-version: ['3.1', '3.2', '3.3']
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
@@ -28,5 +28,18 @@ jobs:
         bundler-cache: true
     - name: Run tests
       run: bundle exec rake
+  lint:
+    strategy:
+      matrix:
+        os: [ 'ubuntu-22.04' ]
+        ruby-version: ['3.3']
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby-version }}
+        bundler-cache: true
     - name: Rubocop
       run: bundle exec rubocop