Fix CI due to different macOS architecture (#246)

Author: lucienlu-aws

.github/workflows/run-unit-tests.yml

@@ -17,7 +17,10 @@ jobs:
       fail-fast: false
       matrix:
         python-version: [3.7, 3.8, 3.9, "3.10", 3.11]
-        os: [ubuntu-latest, macOS-latest, windows-latest ]
+        # TODO: revert macOS-13 back to macOS-latest
+        # macOS-latest switched architectures and does not have older versions of python available
+        # https://github.com/actions/setup-python/issues/856
+        os: [ubuntu-latest, macOS-13, windows-latest ]
 
     steps:
     - uses: actions/checkout@v2