Use distinct name for upload

Author: dandavison

.github/workflows/ci.yml

@@ -75,7 +75,7 @@ jobs:
         uses: actions/upload-artifact@v4
         if: always()
         with:
-          name: junit-xml
+          name: junit-xml-${{ matrix.python }}-${{ matrix.os }}
           path: junit-xml
           retention-days: 30