build with latest ocaml 4.14

[milahu]

Is your feature request related to a problem? Please describe.
build fails with ocaml 4.14

File "_build/.dune/default/vendor/ocaml-lsp-1.4.0/ocaml-lsp-server/vendor/merlin/src/ocaml/utils/dune", line 2, characters 13-25:
2 | (copy_files# 414/*.ml{,i})
                 ^^^^^^^^^^^^
Error: Cannot find directory:
vendor/ocaml-lsp-1.4.0/ocaml-lsp-server/vendor/merlin/src/ocaml/utils/414

https://github.com/AbstractMachinesLab/caramel/tree/main/vendor/ocaml-lsp-1.4.0/ocaml-lsp-server/vendor/merlin/src/ocaml/utils

... has only up to 411 = ocaml 4.11

Describe the solution you'd like
build with latest ocaml 4.14
(ocaml 5.0 would be nice)

Describe alternatives you've considered
build with ocaml 4.11