Add missing constraint

[hhugo]

detected during #26932
The ojs-base lwt constraint is explained in ocsigen/lwt#1042
The picos js_of_ocaml constraint is tracked by ocaml-multicore/picos#332

[mseri]

@zoggy the checksum of ojs-base packages <= 0.5.0 have changed:

• Error in ojs-base.0.5.0: Failed to download the archive. Details: https://framagit.org/zoggy/ojs-base/-/archive/0.5.0/ojs-base-0.5.0.tar.gz (Bad checksum, expected sha256=d12d7419a6952d522a060aed72499127d2b049449980f9472437ddd6ec5e4762)
• Error in ojs-base.0.4.0: Failed to download the archive. Details: https://framagit.org/zoggy/ojs-base/-/archive/0.4.0/ojs-base-0.4.0.tar.gz (Bad checksum, expected sha256=528b1f62e44c762a798e6475f4e53c90e7ae7de2748b00646e01855303231c8f)
• Error in ojs-base.0.3.0: Failed to download the archive. Details: https://framagit.org/zoggy/ojs-base/-/archive/0.3.0/ojs-base-0.3.0.tar.gz (Bad checksum, expected sha256=c14e305872d27692ea1cfa3c57e91eab4c2dc4aaa86e6430b2019f30b769fefa)
• Error in ojs-base.0.2.0: Failed to download the archive. Details: https://framagit.org/zoggy/ojs-base/-/archive/0.2.0/ojs-base-0.2.0.tar.gz (Bad checksum, expected sha256=2eeb8e5f8309c45b13fb19407e984a9bdc34024d40a3444855960ebae2d23630)
• Error in ojs-base.0.1.0: error 60: Upstream check failed: "curl error code 404"
• Error in ojs-base.0.1.0: Weak checksum algorithm(s) provided. Please use SHA-256 or SHA-512. Details: opam field url contains only MD5 as checksum for ojs-base-0.1.0.tar.gz
• Error in ojs-base.0.1.0: Failed to download the archive. Details: https://zoggy.github.io/ojs-base/ojs-base-0.1.0.tar.gz (curl: code 404 while downloading https://zoggy.github.io/ojs-base/ojs-base-0.1.0.tar.gz)

This may help to recover the old archives if you want: https://github.com/ocaml/opam-repository/wiki/FAQ#how-to-find-lost-archives-of-packages
Otherwise we can mark them as no longer available if you prefer