scripts : remove get-wikitext-103.sh (#20543)
It doesn't work and no one seems to use it.
$ wget https://s3.amazonaws.com/research.metamind.io/wikitext/wikitext-103-raw-v1.zip
HTTP request sent, awaiting response... 301 Moved Permanently
Location: unspecified
ERROR: Redirection (301) without location.
Signed-off-by: Adrien Gallouët <angt@huggingface.co>
