Replace deprecated alias Zmod with Z.modulo

[andres-erbsen]

This change adapts math-classes for a future stdlib PR removing Zmod.

The current definition of Zmod in stdlib is as follows:

#[deprecated(since="8.17",note="Use Coq.ZArith.BinIntDef.Z.modulo instead")]
Notation Zmod := Z.modulo (only parsing).

I am looking to remove that definition shortly, and to reuse the name for something incompatible.

Thanks!

[andres-erbsen]

The CI failure appears unrelated:

  Error response from daemon: No such image: coqorg/coq:dev
  Error response from daemon: manifest for coqorg/coq:dev not found: manifest unknown: manifest unknown

[spitters]

Thanks!

Could the CI issue be due to the name change? I guess it's something that shows up on many places on the platform.
@Zimmi48 may know more. I couldn't find the github handle of Sylvain Borgogno...

[SkySkimmer]

Fix ci #135

[spitters]

Thanks @SkySkimmer ! I've restarted the CI.