[TASK] Remove unused folder tree view option

Option ext_noTempRecyclerDirs is circularily used
and always false. It can be removed without harm
and ext_isLinkable() deprecated along the way.

Resolves: #84145
Releases: master
Change-Id: Ibeb949ddb81c919087f894c2839e9bf88c6eb290
Reviewed-on: https://review.typo3.org/56016


Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>