fixes #1687

[affeldt-aist]

Motivation for this change

fixes #1687

I just observed that MathComp-Analysis 1.12.0 fails to compile with HB 1.7.0 and 1.7.1.
We could put the restriction in the opam file of analysis but since the restriction
is already in classical, I chose to modify classical only for the sake of simplicity, wdyt?

Checklist

• added corresponding entries in CHANGELOG_UNRELEASED.md

• added corresponding documentation in the headers

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[proux01]

Thanks, we should probably add that bound to some CI bundle, otherwise we'll likely break it again in the future.