[LyX/master] Add support for zref-clever and zref-vario

[Jürgen Spitzmüller]

Am Montag, dem 24.03.2025 um 11:32 +0100 schrieb Jürgen Spitzmüller:
> I see. The \zlabel requirement has been dropped with 
> v0.4.0 (2023-06-14). Current (with TL 25) is v0.5.1 (2024-11-28).
> 
> I think we should require this version at least

To clarify: by "this version" I mean v0.4.0 (2023-06-14).

-- 
Jürgen