refactor(ocaml): remove tree-sitter support

No *-ts-mode exists for tuareg-mode. There *is* a ocaml-ts-mode, but
it's too rudimentary. The ocaml module will fall back to font-lock rules
so this is not a breaking changing.

modules/lang/ocaml/config.el

@@ -130,10 +130,6 @@
   (opam-switch-set-switch (tuareg-opam-current-compiler)))
 
 
-(when (modulep! +tree-sitter)
-  (add-hook 'tuareg-mode-local-vars-hook #'tree-sitter!))
-
-
 (use-package! dune
   :defer t
   :config