[TASK] Replace prophecy in EXT:core GeneralUtilityTest

Resolves: #98765
Releases: main
Change-Id: Idcb97b1b6c0e1966d06c0ddd23f3c6ecb6cd15fe
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76749


Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Nikita Hovratov <nikita.h@live.de>