Add after migrate hook to activerecord

Hello,

I made a PR to add an after migrate hook to activerecord allowing users to save migration logs for example. I has been marked as stale because it went unnoticed, could someone from the activerecord team have a look at it ? Add after_migrate_hook to db:migrate commands by ylecuyer 路 Pull Request #41072 路 rails/rails 路 GitHub

Thanks :slight_smile: