ci.yml in fb2rb-0.8.0

- old
+ new

@@ -14,11 +14,15 @@
       - name: Lint
         run: bundle exec rake lint
   test:
     strategy:
       matrix:
-        ruby: ['jruby', '2.4', '2.5', '2.6', '2.7', '3.0', '3.1']
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        # Test oldest and newest supported versions
+        ruby: ['jruby-9.2', 'jruby-9.4', '2.5', '3.1']
+        os: [ubuntu-latest, windows-latest]
+        include:
+          - ruby: '3.1'
+            os: macos-latest
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout
         uses: actions/checkout@v3
       - name: Set up Ruby