OpamAction.install_package documentation inaccuracy

[reynir]

The documentation speaks of returning None or Some exn while the type says it returns an Either.t (roughly).

opam/src/client/opamAction.mli

Lines 53 to 58 in 2571522

	(** [install_package t pkg] installs an already built package. Returns
	[None] on success, [Some exn] on error. Do not update opam's
	metadata. See {!build_package} to build the package. *)
	val install_package:
	rw switch_state -> ?test:bool -> ?doc:bool -> ?tools:bool -> ?build_dir:dirname -> package ->
	(OpamFile.Dot_config.t option, exn) OpamCompat.Either.t OpamProcess.job