[TASK] Update swiftmailer to 5.2.1

Resolves: #60227
Releases: 6.3
Change-Id: Ic137136005f117ac491cd8897e702f81169a1c0a
Reviewed-on: https://review.typo3.org/31572
Reviewed-by: Michael Bakonyi <m.bakonyi@civit.de>
Tested-by: Michael Bakonyi <m.bakonyi@civit.de>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>