Refactor GitHub Actions workflow to consolidate OS matrix for testing

Author: Vianpyro

.github/workflows/pytest.yml

@@ -31,10 +31,10 @@ jobs:
         pip install -r requirements.txt
         pip install pytest pytest-cov
 
-    - matrix.os: ubuntu-latest
-      run: python -m pytest --doctest-modules --junitxml=junit/test-results.xml --cov=com --cov-report=xml --cov-report=html
-
-    - matrix.os: macos-latest
+    - matrix:
+      os:
+        - ubuntu-latest
+        - macos-latest
       run: python -m pytest --doctest-modules --junitxml=junit/test-results.xml --cov=com --cov-report=xml --cov-report=html
 
     - matrix.os: windows-latest