Remove explicit consent check during Omniauth registration

This was added very recently to improve rendering of consent errors
in all registration flows. However, for the omniauth case it kicked
us out of the flow that would end up in `render_omniauth_registration_form`.

Thus a failed consent would switch from the omniauth registration form
(that has no password and auth provider inputs, but connects the resulting
user to their original auth provider) to the regular registration form.

By removing this check, confirming the consent during the registration form
is not required anymore. This is at least consistent with remaining omniauth
behaviour. Lacking a required field, the user would be created first and then
asked to confirm the consent in a separate step. This is what happens now as well.

Caveat: Even if the consent is confirmed during the registration form, the second
step will pop up anyways. This issue exists regardless of keeping or removing this
check and is one more thing we need to fix about omniauth registrations.

Author: NobodysNightmare

app/controllers/concerns/accounts/registration.rb

@@ -72,8 +72,6 @@ def register_with_auth_source(user) # rubocop:disable Metrics/AbcSize
     # on-the-fly registration via omniauth or via auth source
     if pending_omniauth_registration?
       user.assign_attributes permitted_params.user_register_via_omniauth
-      return unless consent_given_for_registration?(user)
-
       register_via_omniauth(session, permitted_params.user_register_via_omniauth)
     else
       user.attributes = permitted_params.user

spec/controllers/account_controller_spec.rb

@@ -1365,33 +1365,6 @@ def reset!
         expect(user.identity_url).to eql("google:123545")
       end
 
-      context "with consent required",
-              with_settings: {
-                consent_required: true,
-                consent_info: { en: "# Consent header!" }
-              } do
-        it "renders the registration form with a consent error" do
-          session[:auth_source_registration] = omniauth_hash.merge(
-            omniauth: true,
-            timestamp: Time.current
-          )
-
-          post :register,
-               params: {
-                 user: {
-                   login: "login@bar.com",
-                   firstname: "Foo",
-                   lastname: "Smith",
-                   mail: "foo@bar.com"
-                 }
-               }
-
-          expect(response).to render_template :register
-          expect(assigns(:user).errors[:consent_check]).to contain_exactly(I18n.t("consent.failure_message"))
-          expect(User.find_by_login("login@bar.com")).to be_nil
-        end
-      end
-
       context "when after a timeout expired" do
         before do
           session[:auth_source_registration] = omniauth_hash.merge(