Fix POS tags
_The documentation is not available anymore as the PR was closed or merged._ CI failures are about missing content in the dataset cards or bad tags, and this is unrelated to this PR. Merging :)
We're now using `part-of-speech` and not `part-of-speech-tagging`, see discussion here: https://github.com/huggingface/datasets/commit/114c09aff2fa1519597b46fbcd5a8e0c0d3ae020#r78794777