Fix broken count statements in Active Record 8.0

[jukra]

This fixes the issue discussed here #654 (comment), #652 (comment) and #653 (comment)

I think this caused the second issue with Rails 8.0 and the AS statement with counts not getting wrapped correctly: rails/rails@ba468db

Previously we got the Arel::Nodes for column_name in execute_simple_calculation. With Rails 8 we actually get just the string "article_translations_en"."title" AS __mobility_title_en__, (https://github.com/rails/rails/blob/8-0-stable/activerecord/lib/active_record/relation/calculations.rb#L445)

This is why the count in Countable module does not get called at all (https://github.com/shioyama/mobility/blob/master/lib/mobility/plugins/arel.rb#L32)

Not particularly pretty, but it works because

• Count queries don't include ORDER BY
  • The problematic counting behavior in Rails 8 is bypassed when there's no alias
• Select queries that need proper column aliases do include ORDER BY

I ran the specs locally for also Rails 8.0 and they all passed with this change.

Maybe @shioyama you have a better way in mind on how to fix it?

[n-rodriguez]

@jukra CI is all green with your patch 👍 https://github.com/n-rodriguez/mobility/actions/runs/12072169189

@shioyama LGTM

[shioyama]

Thank you! ❤️