coq-simple-io.dev : remove dune upper bound

[liyishuai]

as the Coq docker images have pinned Dune to 3.14.

[Lysxia]

The upper bound was to work around a bug (discussed here) that manifests itself on opam CI with dune 3.14. So if this PR doesn't pass CI, a more local workaround may be to allow newer dunes only in downstream configs such as QuickChick CI.

[liyishuai]

@erikmd is it worth downgrading the Dune version for coqorg/coq? Currently dev packages either fail the CI here or cannot be installed on the Docker images.
coq-community/docker-base@c6bff64

[erikmd]

Hi @liyishuai ! thanks for the ping.

Sure, this is easy to do. Which version of Dune would be OK?

[erikmd]

Maybe 3.13.1 ?

unless the latest releases 3.15.0 / 3.15.1 would fix the issue you speak about?

https://github.com/ocaml/dune/releases

[erikmd]

Hi @liyishuai, the downgrade is complete, see e.g.:

• https://explore.ggcr.dev/?blob=coqorg/coq@sha256:…&mt=application%2Fvnd.docker.container.image.v1%2Bjson&size=11512&manifest=coqorg/coq:dev@sha256:…
• (URL generated from https://explore.ggcr.dev/?image=coqorg/coq:dev )

Do you think you could file an issue in Dune's repo if it is not already the case?

Also Cc @ybertot FYI

[liyishuai]

Now there's https://github.com/ocaml/dune/releases/tag/3.15.2. Maybe worth testing it on Coq CI.