[TASK] Doctrine: Migrate Scheduler AbstractTask

Resolves: #77370
Releases: master
Change-Id: I158360d29686fbf2b4ecbd6d3670e3ef845667ef
Reviewed-on: https://review.typo3.org/49343


Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Sebastian Bumann <bumann.sebastian@gmail.com>
Tested-by: Sebastian Bumann <bumann.sebastian@gmail.com>