[Kosmos-2] invalid choice: 'generation_obj'

[yujheli]

There is no task choice of 'generation_obj' in the code (i.e., fairseg tasks) in all of the train/evaluation/demo files.

run.py: error: argument --task: invalid choice: 'generation_obj' (choose from 'audio_pretraining', 'audio_finetuning', 'cross_lingual_lm', 'denoising', 'speech_to_text', 'text_to_speech', 'frm_text_to_speech', 'hubert_pretraining', 'language_modeling', 'legacy_masked_lm', 'masked_lm', 'multilingual_denoising', 'multilingual_language_modeling', 'multilingual_masked_lm', 'translation', 'multilingual_translation', 'online_backtranslation', 'semisupervised_translation', 'sentence_prediction', 'sentence_ranking', 'simul_speech_to_text', 'simul_text_to_text', 'speech_to_speech', 'translation_from_pretrained_bart', 'translation_from_pretrained_xlm', 'translation_lev', 'translation_multi_simple_epoch', 'dummy_lm', 'dummy_masked_lm', 'dummy_mt')