[TASK] Exclude StringClassNameToClassConstantRector in rector.yml

As the StringClassNameToClassConstantRector would convert
string class names that are deliberately defined as string,
this rector has been disabled.

Releases: master
Resolves: #89899
Change-Id: Iecbcf2c009885501b0caafe66cb8f5703688c188
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62581


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>