OCaml 5.4.0 release readiness

[Octachron]

This issue tracks the build and readiness information of core platform tools and libraries in preparation for the OCaml 5.4 release. It’s intended as a meta-issue and a home for TODO lists and links to other milestones/issues rather than general discussion (which is welcomed on Discuss or on linked issues).

Packages that are fixed upstream, have a PR ready, or can be used as-is for testing purpose, are in kit-ty-kate/opam-alpha-repository.

Platform tools:

• opam
• dune
• merlin
• lsp-server / vscode-plugin
• odoc (OCaml 5.4 support odoc#1355)
• ocamlformat
• ocp-indent

Ecosystem:

• ocamlfind
• ocamlbuild
• ppxlib
• mdx
• utop (OCaml 5.4 support ocaml-community/utop#500)
• dune-release
• opam-publish

Infrastructure:

• ocaml.org
• docker base containers
• ocaml-ci
• opam-repo-ci

[ddickstein]

Tree-sitter support for labeled tuples, requested in tree-sitter/tree-sitter-ocaml#121