[FEATURE REQUEST] Update to cmdliner 2.0.0

[MisterDA]

Cmdliner 2.0.0 was recently released. The upgrade path should be easy. Presumably some tests of jsoo rely on cmdliner outputs, which might have changed. The author advises against that. Jsoo was tagged incompatible with cmdliner 2.0.0 in the opam-repository, which forbids some upgrades of users of Jsoo.

[hhugo]

I'm confused, jsoo doesn't run test with opam ? do you have the log of the failure ?

[dbuenzli]

Indeed this can be closed see ocaml/opam-repository#28654