8.2
rework the PostmarkDeliveryEvent implementation
CS fixes
Merge branch '6.4' into 7.4
[Mailer] Preserve the sent message object as is when sending it
[Mailer] Harden default IP allowlist for Postmark and Brevo webhook parsers
Add PR template and auto-close PR on subtree split repositories
Add gitignore file for Symfony 4.3
[Mailer][Postmark] Add missing changelog for webhook support
Update license years (last time)
Add call to backers in README files
Bump to php >= 8.4.1
Update XSD references in phpunit.xml.dist files