gh-actions: run in both m1/intel macos

Author: chatziko

.github/workflows/run-tests.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-latest, macos-13, windows-latest]
     steps:
     - uses: actions/checkout@v1