Change dataset in tutorial co-clustering

[fnattino]

• [x] generate low-resolution DayMet-based datasets (first-leaf, first-bloom or last-day-of-freeze)
• [x] modify tutorial to include one of these

[fnattino]

Script to create low-resolution version of the dataset is here: https://github.com/phenology/co_and_triclustering/tree/main/notebooks/stable/tutorial

Dataset (in Zarr format) uploaded to tutorial: https://cgc-tutorial.readthedocs.io/en/latest/notebooks/coclustering.html