Remove deprecated tasks (#2)

- Remove deprecated tasks (5892a76e382d772ccdd527189e631bb9b1326bc0)

video_tags.py

@@ -22,7 +22,6 @@ import struct
 import numpy as np
 
 import datasets
-from datasets.tasks import ImageClassification
 
 
 _CITATION = """\
@@ -72,12 +71,6 @@ class MNIST(datasets.GeneratorBasedBuilder):
             supervised_keys=("image", "label"),
             homepage="http://yann.lecun.com/exdb/mnist/",
             citation=_CITATION,
-            task_templates=[
-                ImageClassification(
-                    image_column="image",
-                    label_column="label",
-                )
-            ],
         )
 
     def _split_generators(self, dl_manager):