[TASK] TemplateService: Remove old paths from allowedPaths-list

We don't have the t3lib-directory anymore.

Change-Id: Icef845e0ae1fc25a51cd01fa2452751d14b362c5
Resolves: #55433
Releases: 6.2
Reviewed-on: https://review.typo3.org/27125
Tested-by: Georg Ringer
Reviewed-by: Benjamin Mack
Tested-by: Benjamin Mack