Fix Rails/SaveBang Rubocop offenses for email handlers

.rubocop_manual_todo.yml

@@ -250,8 +250,6 @@ Rails/SaveBang:
     - 'spec/lib/gitlab/database/custom_structure_spec.rb'
     - 'spec/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers_spec.rb'
     - 'spec/lib/gitlab/database_importers/self_monitoring/project/create_service_spec.rb'
-    - 'spec/lib/gitlab/email/handler/create_note_handler_spec.rb'
-    - 'spec/lib/gitlab/email/handler/unsubscribe_handler_spec.rb'
     - 'spec/lib/gitlab/gfm/reference_rewriter_spec.rb'
     - 'spec/lib/gitlab/git_access_spec.rb'
     - 'spec/lib/gitlab/gitaly_client/object_pool_service_spec.rb'

changelogs/unreleased/issue-220040-fix-rails-savebang-email-handlers.yml

+---
+title: Fix Rails/SaveBang Rubocop offenses for email handlers
+merge_request: 58095
+author: Huzaifa Iftikhar @huzaifaiftikhar
+type: fixed

spec/lib/gitlab/email/handler/unsubscribe_handler_spec.rb

@@ -74,7 +74,7 @@ RSpec.describe Gitlab::Email::Handler::UnsubscribeHandler do
 
   context 'when the noteable could not be found' do
     before do
-      noteable.destroy
+      noteable.destroy!
     end
 
     it 'raises a NoteableNotFoundError' do