[ANN] Bignums release 9.0.0

We just released Bignums 9.0.0 to remove the `[_]%bigN`, `[_]%bigZ`
and `[_]%bigQ` notations that were causing too many conflicts (for
instance with `ListNotations` or primitive arrays). We recommend using
`BigN.to_Z`, `BigZ.to_Z` and `BigQ.to_Q` as backward compatible
replacements (until we find a less conflicting notation, suggestions
welcomed: Remove the [ _ ] notations by proux01 · Pull Request #74 · coq-community/bignums · GitHub).

OPAM packages were published for Coq 8.13 to 8.17+rc1 and the Docker
images were updated. If you have released packages that use the
removed notations, a `coq-bignums {< "9~"}` constraint should be added
(the OPAM packages in the coq.inria.fr repos already have it).

Érik and Pierre, comaintainers of Bignums