[MacPorts] #59429: ocaml: Update to 4.09.0 and fix livecheck

[MacPorts]

#59429: ocaml: Update to 4.09.0 and fix livecheck
-------------------------+----------------------
  Reporter:  ryandesign  |      Owner:  pmetzger
      Type:  update      |     Status:  assigned
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:
Resolution:              |   Keywords:
      Port:  ocaml       |
-------------------------+----------------------

Comment (by pmetzger):

 Yah, I know, MacPorts is pretty far behind on this. It's just so messy
 dealing with all the associated upgrades. If you can use MacPorts to
 install opam and then use opam to install your real OCaml packages that's
 probably for the best for now. If you want to help me figure out
 everything that will break if we go to 4.10 (among other things, it's no
 longer possible to request writable strings with a compiler flag and that
 breaks even more packages) I'm happy to do so. I will probably get to this
 myself in a couple of months.

-- 
Ticket URL: <https://trac.macports.org/ticket/59429#comment:8>
MacPorts <https://www.macports.org/>
Ports system for macOS