ci: update ci workflow

Author: rubysamurai

.github/workflows/ci.yml

@@ -2,15 +2,16 @@ name: CI
 on: [push, pull_request]
 jobs:
   tests:
-    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.4, 2.5, 2.6, 2.7, '3.0', 3.1, head, truffleruby, truffleruby-head, truffleruby+graalvm, truffleruby+graalvm-head]
-    name: Ruby ${{ matrix.ruby }}
+        os: [ubuntu-latest, macos-latest]
+        ruby: ['2.4', '2.5', '2.6', '2.7', '3.0', '3.1', '3.2', '3.3', head, truffleruby, truffleruby-head]
+    runs-on: ${{ matrix.os }}
+    name: Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with: