Prepare for 5.2 AST bump

[patricoferris]

In preparation for ocaml/opam-repository#27478 there is WIP documentation about the AST bump on the ppxlib wiki: https://github.com/ocaml-ppx/ppxlib/wiki/Upgrading-to-ppxlib-0.36.0

[jmid]

Thanks! So IIUC, the previous versions need a ppxlib.0.35 upper bound, and then it would be nice to release a version with this patch once ppxlib.0.36 is available from the opam-repo, right?

[patricoferris]

That's correct :)) Once we 0.36.0 is released, having a release with >=0.36.0 would be great. That opam file change should be a part of this PR but let's wait for the actual release so CI will pick it up.

[jmid]

I just merged #335 (incl. suitable opam updates) and rebased on main.

The CI is still failing unfortunately:
https://github.com/c-cube/qcheck/actions/runs/13708003567/job/38337945815?pr=331

[ERROR] Package conflict!
  * No agreement on the version of ppxlib:
    - deps-of-ppx_deriving_qcheck → ppx_deriving >= 5.2.1 → ppxlib < 0.36.0
    - deps-of-ppx_deriving_qcheck → ppxlib >= 0.36.0

AFAICS this is because the latest ppx_deriving needs ppxlib < 0.36.0
https://github.com/ocaml/opam-repository/blob/master/packages/ppx_deriving/ppx_deriving.6.0.3/opam#L22
as such we need that one to support ppxlib.0.36.0 too... 😬