Remove unnecessary @inlines (when an odoc bug is fixed)

[NatKarmios]

Odoc currently has a bug with nested @canonical tags (discussed in this conversation in the OCaml Discord server); in order to get the desired output in documentation, I've had to use some module @includes that aren't the cleanest.

For example, this is the contents of Debugger_lifter.ml:

(** @canonical Gillian.Debugger.Lifter

  The mechanism for lifting execution of GIL commands to a target language. *)

include Lifter

module Gil_lifter = struct
  (** @inline*)
  include Gil_lifter
end

module Gil_fallback_lifter = struct
  (** @inline *)
  include Gil_fallback_lifter
end