Run CI on MacOS too

Author: purcell

.github/workflows/ci.yml

@@ -5,7 +5,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest]
+        os: [ubuntu-latest, macos-latest]
         # Due to https://github.com/actions/runner/issues/849, we have to use quotes for '3.0'
         ruby: ['3.0', '3.1', '3.2', '3.3']
     runs-on: ${{ matrix.os }}