Core MediaWiki already defines ordered lists for non-Western numerals in i18n-ordered-lists.less: Persian, Hindi, Odia, and a few more.
However, we need a few more, but they don't have standardized list-style-type values. These writing systems are Arabic, Ol Chiki (Santali), Meetei (Manipuri), and N'Ko.
It's possible to do this using CSS @counter-style. When I first reported this task, this only worked on Firefox, but now it works in Chromium, too (upstream Chromium bug). I nevertheless added this to Common.css and Mobile.css in the Wikipedias in these languages, because it's better than nothing. Eventually it should be moved to core.