[WP] Remove unused option '-wp-why-lib'

src/plugins/wp/wp_parameters.ml

@@ -744,15 +744,6 @@ module Why3 =
     let help = "Command to run Why-3 (default: 'why3')"
   end)
 
-let () = Parameter_customize.set_group wp_prover_options
-module WhyLibs =
-  String_list
-    (struct
-      let option_name = "-wp-why-lib"
-      let arg_name = "*.why"
-      let help = "Additional libraries for Why"
-    end)
-
 let () = Parameter_customize.set_group wp_prover_options
 let () = Parameter_customize.no_category ()
 module WhyFlags =

src/plugins/wp/wp_parameters.mli

@@ -113,7 +113,6 @@ module CoqTactic: Parameter_sig.String
 module Hints: Parameter_sig.Int
 module TryHints: Parameter_sig.Bool
 module Why3: Parameter_sig.String
-module WhyLibs: Parameter_sig.String_list
 module WhyFlags: Parameter_sig.String_list
 module AltErgo: Parameter_sig.String
 module AltGrErgo: Parameter_sig.String