[BUGFIX] Cleanup testing framework integration

Clean up removed autoload definitions, use the correct
env var and remove the TYPO3_PATH_PACKAGE env var, which
isn't required.

Resolves: #80651
Releases: master
Change-Id: I5dcbad22bb6f1bac76c3d8de9a677a41ac8bd647
Reviewed-on: https://review.typo3.org/52331


Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>