They're not exactly zombies or ghosts. They're spectral beings in moonlight but have physical form othertimes. How would this be classified?
The transcript only refers to them as skeletons.
The Pirates of the Caribbean wiki refers to them as "Cursed."
If neither of these suit you, then I would say simply "the undead" would be the best term, based on what Barbosa says:
We are not among the living and so we cannot die...but neither are we dead! We have all the desires of the living, but cannot satisfy them!