Upgrade MediaWiki to 1.40 to support the en-au language

[andrewharvey]

MediaWiki 1.40 added en-au as a language. It is desirable to have this language enabled on the OSM wiki to enable localised tag descriptions for editors to consume.

Would it be possible to have the current version 1.39.5 upgraded?

(this request spun out of the discussion at https://discord.com/channels/413070382636072960/704832584328151040/1178834387610112111)

[kurisubrooks]

+1 - We recently had a case in Australia where a mapper was removing certain tags due to Presets and Descriptions having American-specific terms, which caused confusion. Would love to be able to contribute some more Australia-specific descriptions for the local context (in line with the Australian Tagging Guidelines)

[andrewharvey]

Upon further investigation I'm not so sure if this upgrade would unlock Australian English as a language.

On wikidata, I still can't choose Australian English from the Universal Language Selector, and when I use uselang=en-au it registers the language as "Australian English" but still gives me an error when saving

[Firefishy]

Reference en-au is available in https://github.com/wikimedia/mediawiki-extensions-Wikibase/blob/REL1_40/lib/includes/WikibaseContentLanguages.php release.

We're a small team administering the site. Long Term Support (LTS) releases (currently 1.39.x) make our life much easier. My preference would be to wait for the next LTS release of mediawiki.