codecov changes to workflow

.github/workflows/python-plain-run-test.yml

@@ -39,7 +39,12 @@ jobs:
 #    - name: Test with pytest
 #      run: |
 #        pytest
-    - name: Test with plain runs
+    - name: Run tests and collect coverage
       run: |
-        # pytest -v
-        # bash ./tests/run_plain_tests.sh
+        pip install pytest-cov
+        pytest --cov=./ --cov-report=xml
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v3
+      with:
+        fail_ci_if_error: true
+        verbose: true