Attempt to reinstated the macOS 13 runner (again).

Hopefully fixes #85

Author: lgarron

.github/workflows/test.yml

@@ -4,7 +4,7 @@ jobs:
   test:
     strategy:
       matrix:
-        os: [macos-12, macos-14]
+        os: [macos-12, macos-13, macos-14]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout code