lang/ocaml-nox11: Remove redundant sub port

X11 support has been removed upstream from ocaml, menaing the UI
support in the ocaml compiler.

Ability to compile ports with X11 UI is supported and depends on
other components available in the ports tree.

So remove this redundant port since the provided functionality is
identical to the lang/ocaml port.

PR: 277676
Approved by: michael.grunewald@laposte.net (maintainer timeout)