AO3-7397 Remove redundant test

Author: nicolacleary

spec/controllers/skins_controller_spec.rb

@@ -133,18 +133,6 @@
     end
   end
 
-  describe "GET #preview" do
-    context "with a public site skin" do
-      let(:skin) { create(:skin, :public) }
-
-      it "redirects to the configured preview page" do
-        get :preview, params: { id: skin.id }
-        it_redirects_to_simple("#{ArchiveConfig.SKIN_PREVIEW_URL}?site_skin=#{skin.id}")
-        expect(flash[:notice]).to include("You are previewing the skin #{skin.title}.")
-      end
-    end
-  end
-
   describe "PUT #update" do
     shared_examples "an action guests and random logged-in users can't access" do |attribute:, value:|
       context "when logged in as a user who is not the skin author" do