Put out Onionoo 5.2-1.12.0

With legacy/trac#22594 (moved) and legacy/trac#24256 (moved) being merged and legacy/trac#25700 (moved) being close to getting merged, should we consider putting out a 5.2-1.12.0 release this week before we put out 6.0-1.x.x in 10 days from now?

(Note to self: update metrics-web for legacy/trac#24256 (moved) as part of this!)