Use database_cleaner-active_record gem instead of database_cleaner

What does this MR do and why?

database_cleaner v1.7.0 is outdated and database_cleaner is now separated into multiple gems.　　 https://github.com/DatabaseCleaner/database_cleaner#gem-setup

This MR introduces database_cleaner-active_record instead of database_cleaner.

The new gem has changed the way multiple ORMs are configured.

before	after
DatabaseCleaner[:active_record, { :connection => :two }]	DatabaseCleaner[:active_record, db: :two]
https://github.com/DatabaseCleaner/database_cleaner/blob/v1.7.0/README.markdown#how-to-use-with-multiple-orms	https://github.com/DatabaseCleaner/database_cleaner/blob/main/README.markdown#how-to-use-with-multiple-orms

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.