Use matrix name in coverage artifact

Author: hansthen

.github/workflows/test_code.yml

@@ -56,5 +56,5 @@ jobs:
       if: always()
       uses: actions/upload-artifact@v4
       with:
-        name: coverage-test-code
+        name: coverage-test-code-${{ matrix.os }}-${{ matrix.python_version }}
         path: /tmp/.coverage.*