[TASK] Remove unused locallang file for clearcache menu

The locallang file is not used in the core anymore since 6.2

Resolves: #78564
Releases: master
Change-Id: I8b0cf2fd779e0a017de15c1c778518a6f7f14ed1
Reviewed-on: https://review.typo3.org/50497


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Tested-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>