[TASK] Remove replace for EXT:about in composer.json

The extesion "about" is moved to EXT:backend and can
safely be removed in composer.json.

Resolves: #94967
Related: #91888
Releases: master
Change-Id: I61e00b78ea12c1226fe35244778612e1d82fd054
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70604


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>