See https://www.wikidata.org/wiki/Q42?uselang=en-gb
The sitelink headings are in Welsh, e.g. "Wiciddyfynnu" instead of "Wikiquote" and most of the links in the footer are too, e.g. "Golwg teclyn symudol" instead of "Mobile view"
Backports:
https://gerrit.wikimedia.org/r/704612
https://gerrit.wikimedia.org/r/704611