Revert "refactor detection of class CategoryYearMonthDay in a less nonsense way"

Revert "refactor detection of class CategoryYearMonthDay in a less nonsense way (part 2)"

This reverts commit c7ee242dcc9996e747077779ccb32fe4877b62b9.

This reverts commit a91335eb040c30e902df328dbca40b1aa604d71e.

The assumption was wrong. There are many classes extending CategoryYearMonthDay.
So that part of the condition was substantially always true, so, that bug
was causing the creation of empty categories.

Bug reported by the kind GryffindorD:

https://it.wikipedia.org/wiki/Discussioni_utente:BotCancellazioni#c-Valerio_Bozzolan-20260818160000-GryffindorD-20260818151900