[TASK] Unit test fails with recent PHP releases

Recent PHP unit minor upgrades fixed a bug in DateTimeZone reflection
which is used as test object in our ObjectAccess reflection tests.
Make the test a bit less strict to cope with youngest and older
PHP versions at the same time.

Change-Id: Iaf2290872938f4c04a3307b0fe73c933ca7d69d8
Resolves: #81239
Releases: master, 8.7, 7.6
Reviewed-on: https://review.typo3.org/52816


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>