revert mmlu tasks

lm_eval/tasks/mmlu/default/mmlu_virology.yaml

 "dataset_name": "virology"
 "description": "The following are multiple choice questions (with answers) about virology.\n\
   \n"
+"group": "mmlu_other"
+"group_alias": "other"
 "include": "_default_template_yaml"
 "task": "mmlu_virology"
 "task_alias": "virology"

lm_eval/tasks/mmlu/default/mmlu_world_religions.yaml

 "dataset_name": "world_religions"
 "description": "The following are multiple choice questions (with answers) about world\
   \ religions.\n\n"
+"group": "mmlu_humanities"
+"group_alias": "humanities"
 "include": "_default_template_yaml"
 "task": "mmlu_world_religions"
-"task_alias": "world religions"
+"task_alias": "world_religions"