chore(ci): update codecov action from v5 to v6

Author: tanbro

.github/workflows/python-package.yml

@@ -172,7 +172,7 @@ jobs:
           uv run --no-dev coverage xml
 
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           token: ${{ secrets.CODECOV_TOKEN }}