Remove changes from v2 as it's obsolete

lib/expression/v2/callbacks.ex

@@ -97,25 +97,12 @@ defmodule Expression.V2.Callbacks do
       function_exported?(Standard, vargs_function_name, 2) ->
         {:vargs, Standard, vargs_function_name}
 
-      # Check if the wrong number of arguments was provided
-      wrong_arity_but_function_exists?(module, exact_function_name) ->
-        {:error, "wrong number of arguments to #{function_name}."}
-
-      # Check if the wrong number of arguments was provided
-      wrong_arity_but_function_exists?(Standard, exact_function_name) ->
-        {:error, "wrong number of arguments to #{function_name}."}
-
       # Otherwise fail
       true ->
         {:error, "#{function_name} is not implemented."}
     end
   end
 
-  defp wrong_arity_but_function_exists?(module, function_name)
-       when is_atom(module) and is_atom(function_name) do
-    Enum.any?(0..20, fn arity -> Kernel.function_exported?(module, function_name, arity) end)
-  end
-
   defmacro __using__(_opts) do
     quote do
       def callback(module \\ __MODULE__, context, function_name, args)