Fix NC Mall Styling Studio import

They made a small change to the API call! Fixed now!

The other NC Mall syncing stuff to get current NC cost is broken, but
that seems like a MUCH bigger change, so I won't bother just yet.

app/services/neopets/nc_mall.rb

@@ -60,7 +60,7 @@ module Neopets::NCMall
 					["Cookie", "neologin=#{neologin}"],
 					["X-Requested-With", "XMLHttpRequest"],
 				],
-				{tab:, mode: "getStyles", species: species_id}.to_query,
+				{tab:, mode: "getAvailable", species: species_id}.to_query,
 			) do |response|
 				if response.status != 200
 					raise ResponseNotOK.new(response.status),

spec/services/nc_mall_spec.rb

@@ -58,7 +58,7 @@ RSpec.describe Neopets::NCMall, type: :model do
 						"Cookie": "neologin=STUB_NEOLOGIN",
 						"User-Agent": Rails.configuration.user_agent_for_neopets,
 					},
-					body: "mode=getStyles&species=2&tab=#{tab}",
+					body: "mode=getAvailable&species=2&tab=#{tab}",
 				)
 		end