Fix e2e test_16_statistics
Fix e2e `test_16_statistics`. as this file was added after branch (https://github.com/huggingface/datasets-server/tree/update-datasets-2.14) was created from main.

This fix is necessary after the refactoring introduced by:
- #1616

Fix e2e test_16_statistics: Fix e2e `test_16_statistics`. as this file was added after branch (https://github.com/huggingface/datasets-server/tree/update-datasets-2.14) was created from main.

This fix is necessary after the refactoring introduced by:
- #1616
