[BUGFIX] Use var path from Environment in tests

Some tests still use hardcoded 'typo3temp' for creating files and folders.
Where possible, this has been changed to use varPath from Environment class
instead.

Resolves: #88551
Releases: master
Change-Id: I2d9a8edfb3fb33cc8f86f8e487603d0c72ef3ff0
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/60946


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>