Add a deprecation warning for `__int__()`

Do we want to give users a grace period, in case they need to support two cuda->bindings versions for a while?

Concretely:

In the next release, deprecate only in the documentation.

Only with the next minor release bump: actually raise DeprecationWarning.

@leofang WDYT about introducing a "Phased deprecations" section somewhere, so we don't forget in the future.

E.g. for this case:

__int__() method for type A, B, C were informally deprecated in cuda-bindings release vX.Y.Z. DeprecationWarning will be raised starting with release vX.Y+1.0.

Originally posted by @rwgk in https://github.com/NVIDIA/cuda-python/issues/773#issuecomment-3109349954

Commencez par localiser les implémentations de int() et la documentation de release ou de dépréciation du projet ; l’issue ne mentionne aucun fichier ni test. Confirmez quels types sont couverts et convenez de déterminer si cette release doit documenter la dépréciation ou n’émettre DeprecationWarning qu’après la prochaine minor release. C’est terminé lorsque le comportement par phases est documenté et implémenté de manière cohérente.