Rails 7.1 changes established database connection after calling `rails db:test:prepare` for multi-database apps about rails

[justinko]

This fixes it but I don't think it's the direction we want to go in: justinko@2fc0ded

I think there's some confusion about responsibility between database_tasks.rb and databases.rake. I'm looking into it.

[zzak]

@justinko I think a problem with that approach is that those tasks already call establish_connection, e.g.:

rails/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb

Line 28 in 965b8c3

establish_connection(public_schema_config)

[justinko]

Which is essentially idempotent/no-op as connection on the next line is the same connection from with_temporary_connection (in my branch). At least it is with the mysql tasks, as that's all I've tested so far.

Not saying this is the correct approach but we do need to find a clean way to restore to the original db config.

[justinko]

@zzak ready for review #51862