- Fix #54830 (This indirectly fix the issue)
- ### Problem

  The `create_or_find_by` method doesn't allow rolling back
  a transaction. This is a different behaviour than its counterpart
  method `find_or_create_by`.
  The reason is because we are in the double transaction edge case and
  the outer transaction doesn't see the rollback.

  ### Details

  ```ruby
  class User < ApplicationRecord
    after_save do
      raise ActiveRecord::Rollback
    end
  end

  User.find_or_create_by(name: "John") => Correctly rolled back
  User.create_or_find_by(name: "John") => Does not roll back
  ```

  ### Solution

  We need to be able to know whether the inner transaction succeeded,
  which is not possible using `.create`, as this method always returns
  the record (rather than the status of the transaction).
  https://github.com/rails/rails/blob/1eac7f27748ffa43c5ce91c036c928fc22d4c597/activerecord/lib/active_record/persistence.rb#L39

  Using `new` followed by a save is equivalent to `create`, but
  with `save` we get the transaction return status and we can
  properly rollback the outer transaction.