HTTP error 429 for test datasets

**Describe the bug** We get an HTTP error 429 from Zenodo now. **To Reproduce** Steps to reproduce the behavior: 1. pytest tests/test_available_data.py **Expected behavior** No HTTP error. **System [please complete the following information]:** - OS: MacOS 15.5; GitHub actions. - Language Version: Python 3.13 - Virtual environment: conda