[TASK] Deprecate AbstractPlugin

In addition to #98281 in TYPO3 v12.0, "pibase"
AbstractPlugin now actively logs a deprecation
message.

Resolves: #100639
Related: #98281
Releases: main
Change-Id: Ib8d17f745c9cefa7bfb76a9acfeac96c8a20234f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78686


Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>