[TASK] Add final private constructor to GeneralUtility

GeneralUtility is a class with only static methods and
a class comment stated for years not to instantiate it.

Since there is a possibility to prevent instantiations
of classes with private constructors, one has added to
this class and on top is has been marked final.

Releases: master
Resolves: #91043
Change-Id: I15e2dfa98b2a30149f9f0efed31281d5d01d4efa
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64181


Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>