Use MailPit instead of MailHog as drop-in replacement

[ilnytskyi]

As drop-in replacement for mailhog https://github.com/axllent/mailpit

MailPit also supports better handling of attachments

Current MailHog build https://github.com/magento/magento-cloud-docker/blob/df20834690e40b7be21eff20da3074ef409c190c/images/php/8.3-fpm/Dockerfile#L5C34-L5C71 isn't maintained regularly, last update was in 2016 https://github.com/mailhog/mhsendmail/releases/tag/v0.2.0

It's proven by Lavarel ecosystem and recommended in Laravel docs: https://laravel.com/docs/11.x/mail#mailtrap