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

multi_lexsum.py

@@ -3,7 +3,6 @@ import os
 from typing import Any, Dict, List, Tuple, Union
 
 import datasets
-from datasets.tasks import Summarization
 
 logger = datasets.logging.get_logger(__name__)
 
@@ -100,9 +99,6 @@ class MultiLexsum(datasets.GeneratorBasedBuilder):
                 supervised_keys=None,
                 homepage=_HOMEPAGE,
                 citation=_CITATION,
-                task_templates=[
-                    Summarization(text_column="source", summary_column="summary/long")
-                ],
             )
         elif self.config.name == "v20230518":
             return datasets.DatasetInfo(
@@ -155,9 +151,6 @@ class MultiLexsum(datasets.GeneratorBasedBuilder):
                 supervised_keys=None,
                 homepage=_HOMEPAGE,
                 citation=_CITATION,
-                task_templates=[
-                    Summarization(text_column="source", summary_column="summary/long")
-                ],
             )
 
     def _split_generators(self, dl_manager):