## Description
The following keys should be updated to take advantage of union types when they are available (see T292892 & T296326).
Z6010K2: Should allow for `Z19677/Rational number` and also `Z24/void`
Z6010K3: Should allow for `Z19677/Rational number` and also `Z24/void`
Z6011K3: Should allow for `Z19677/Rational number` and also `Z24/void`
Z6011K4: Should allow for `Z6091/Wikidata item reference` and also `Z24/void`
Z20342K1: Should allow for `Z16098/Gregorian calendar month` and also `Z24/void`
**Desired behavior/Acceptance criteria (returned value, expected error, performance expectations, etc.)**
* ...
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## Completion checklist
* [ ] Before closing this task, review one by one the checklist available here: https://www.mediawiki.org/wiki/Abstract_Wikipedia_team/Definition_of_Done#Back-end_Task/Bug_completion_checklist