[TASK] Replace last occurrences of PATH_site with Environment API

Resolves: #85285
Releases: master
Change-Id: I4d12f7add6f536b3a412e554c8a6c4d64fd677e4
Reviewed-on: https://review.typo3.org/57241


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>