[TASK] Remove a heavy-mocking unit test

getPagesTSconfigWorksWithoutInitializedBackendUser()
does nothing insanely useful and is more a burden
than a helper when the implementation of the
test subject is changed.

Resolves: #99112
Releases: main
Change-Id: I7377c17283fcfe641bb46356fd5cd1e91b92552d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76656


Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>