Remove non-api tests from api spec

The removed tests are just aeftover.
The tests are already covered in the RegistrationController specs.

spec/controllers/registrations_controller_spec.rb

@@ -30,6 +30,7 @@ describe RegistrationsController do
 
       it 'renders new template and sets the resource variable' do
         expect(subject).to render_template(:new)
+        expect(response).to have_gitlab_http_status(200)
         expect(assigns(:resource)).to be_a(User)
       end
     end
@@ -47,6 +48,7 @@ describe RegistrationsController do
 
       it 'renders new template and sets the resource variable' do
         subject
+        expect(response).to have_gitlab_http_status(302)
         expect(response).to redirect_to(new_user_session_path(anchor: 'register-pane'))
       end
     end

spec/requests/api/users_spec.rb

@@ -633,32 +633,6 @@ describe API::Users do
     end
   end
 
-  describe "GET /users/sign_up" do
-    context 'when experimental signup_flow is active' do
-      before do
-        stub_experiment_for_user(signup_flow: true)
-      end
-
-      it "shows sign up page" do
-        get "/users/sign_up"
-        expect(response).to have_gitlab_http_status(200)
-        expect(response).to render_template(:new)
-      end
-    end
-
-    context 'when experimental signup_flow is not active' do
-      before do
-        stub_experiment_for_user(signup_flow: false)
-      end
-
-      it "redirects to sign in page" do
-        get "/users/sign_up"
-        expect(response).to have_gitlab_http_status(302)
-        expect(response).to redirect_to(new_user_session_path(anchor: 'register-pane'))
-      end
-    end
-  end
-
   describe "PUT /users/:id" do
     let!(:admin_user) { create(:admin) }