[arch-devops] Update to MediaWiki 1.35

[Pierre Schmitz]

Hi all,

I am preparing an update to our MediaWiki instance from 1.34 to 1.35.
See https://github.com/archlinux/archwiki/pull/36 The overall diff is
probably useless; individual commits are probably more readable. Also
huge thanks to Jakub Klinkovský for doing the initial work and giving
great input!

According to the changelog the migration script could take hours. As I
had some bad experience with an 6 hour downtime I'd like to test this
beforehand :-). Could someone provide me with a database dump of the
wiki so I can check how long the migration would take? (I cannot login
to Apollo)

Greetings,

Pierre