Fix Rails/SaveBang offenses for auth controllers

Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/220040

.rubocop_manual_todo.yml

@@ -182,8 +182,6 @@ Rails/SaveBang:
     - 'spec/controllers/groups/runners_controller_spec.rb'
     - 'spec/controllers/groups/uploads_controller_spec.rb'
     - 'spec/controllers/groups_controller_spec.rb'
-    - 'spec/controllers/oauth/authorizations_controller_spec.rb'
-    - 'spec/controllers/omniauth_callbacks_controller_spec.rb'
     - 'spec/controllers/profiles/emails_controller_spec.rb'
     - 'spec/controllers/profiles/notifications_controller_spec.rb'
     - 'spec/controllers/projects_controller_spec.rb'

spec/controllers/oauth/authorizations_controller_spec.rb

@@ -54,7 +54,7 @@ RSpec.describe Oauth::AuthorizationsController do
   shared_examples "Implicit grant can't be used in confidential application" do
     context 'when application is confidential' do
       before do
-        application.update(confidential: true)
+        application.update!(confidential: true)
         params[:response_type] = 'token'
       end
 
@@ -96,7 +96,7 @@ RSpec.describe Oauth::AuthorizationsController do
         end
 
         it 'deletes session.user_return_to and redirects when skip authorization' do
-          application.update(trusted: true)
+          application.update!(trusted: true)
           request.session['user_return_to'] = 'http://example.com'
 
           subject

spec/controllers/omniauth_callbacks_controller_spec.rb

@@ -60,7 +60,7 @@ RSpec.describe OmniauthCallbacksController, type: :controller do
       let(:extern_uid) { 'my-uid' }
 
       before do
-        user.update(failed_attempts: User.maximum_attempts.pred)
+        user.update!(failed_attempts: User.maximum_attempts.pred)
         subject.response = ActionDispatch::Response.new
       end
 
@@ -233,7 +233,7 @@ RSpec.describe OmniauthCallbacksController, type: :controller do
           before do
             stub_env('IN_MEMORY_APPLICATION_SETTINGS', 'false')
             settings = Gitlab::CurrentSettings.current_application_settings
-            settings.update(disabled_oauth_sign_in_sources: [provider.to_s])
+            settings.update!(disabled_oauth_sign_in_sources: [provider.to_s])
           end
 
           it 'prevents login via POST' do
@@ -299,7 +299,7 @@ RSpec.describe OmniauthCallbacksController, type: :controller do
           before do
             stub_omniauth_setting(enabled: true, auto_link_user: true, allow_single_sign_on: ['atlassian_oauth2'])
 
-            user.destroy
+            user.destroy!
           end
 
           it 'denies sign-in if sign-up is enabled, but block_auto_created_users is set' do
@@ -381,7 +381,7 @@ RSpec.describe OmniauthCallbacksController, type: :controller do
 
     context 'sign up' do
       before do
-        user.destroy
+        user.destroy!
       end
 
       it 'denies login if sign up is enabled, but block_auto_created_users is set' do