Remove deprecated tasks

This dataset uses `tasks`, which are deprecated and will raise an error after the next major release of `datasets`. See: https://github.com/huggingface/datasets/pull/6999

rock-glacier-dataset.py

@@ -17,7 +17,6 @@ import os
 import re
 
 import datasets
-from datasets.tasks import ImageClassification
 
 #datasets.logging.set_verbosity_debug()
 #datasets.logging.set_verbosity_info()