Breaking: #105809 - AfterMailerInitializationEvent removed

See forge#105809

Description

The event \TYPO3\CMS\Core\Mail\Event\AfterMailerInitializationEvent has been removed. This event became useless with the introduction of the symfony based mailer in TYPO3 v10 and was only able to influence the core handling by calling the @internal marked method injectMailSettings() after the settings have already been determined within the core mailer. The event has been removed since it did not fit a useful use case anymore.

Impact

Event listeners registered for this event will no longer be triggered.

Affected installations

This event did not fit much purpose since the switch to the symfony based mailer anymore and is probably not used in many instances. The extension scanner will find usages.

Migration

Check if this event could be substituted by reconfiguring $GLOBALS['TYPO3_CONF_VARS']['MAIL'] , or by listening on \TYPO3\CMS\Core\Mail\Event\BeforeMailerSentMessageEvent event instead.