Delete legacy JSON metadata

Delete legacy `dataset_infos.json`.

dataset_infos.json

@@ -1 +0,0 @@
-{"default": {"description": "Language modeling resources to be used in conjunction with the LibriSpeech ASR corpus.\n", "citation": "@inproceedings{panayotov2015librispeech,\n  title={Librispeech: an ASR corpus based on public domain audio books},\n  author={Panayotov, Vassil and Chen, Guoguo and Povey, Daniel and Khudanpur, Sanjeev},\n  booktitle={Acoustics, Speech and Signal Processing (ICASSP), 2015 IEEE International Conference on},\n  pages={5206--5210},\n  year={2015},\n  organization={IEEE}\n}\n", "homepage": "http://www.openslr.org/11", "license": "", "features": {"text": {"dtype": "string", "id": null, "_type": "Value"}}, "supervised_keys": {"input": "text", "output": "text"}, "builder_name": "librispeech_lm", "config_name": "default", "version": {"version_str": "0.1.0", "description": null, "datasets_version_to_prepare": null, "major": 0, "minor": 1, "patch": 0}, "splits": {"train": {"name": "train", "num_bytes": 4418577129, "num_examples": 40418260, "dataset_name": "librispeech_lm"}}, "download_checksums": {"http://www.openslr.org/resources/11/librispeech-lm-norm.txt.gz": {"num_bytes": 1507274412, "checksum": "927d47656638c2ca93566640e56bcbeb2aa4ca237b8490fe1eff7d6e610a53c7"}}, "download_size": 1507274412, "dataset_size": 4418577129, "size_in_bytes": 5925851541}}