[TASK] Disable sub-request error pages by default

We can re-enable them by default when we're much more certain
that stateful services have been removed or properly handled.

Resolves: #95253
Related: #95174
Related: #94402
Releases: master
Change-Id: I820f48797a21ded4ce49b74ce11b9c1eb164b353
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71107


Tested-by: core-ci <typo3@b13.com>
Tested-by: Simon Gilli <typo3@gilbertsoft.org>
Tested-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Simon Gilli <typo3@gilbertsoft.org>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>