[TASK] Prevent requiring "typo3conf" for Composer mode in Dir. Status

Currently both the Install Tool and Environment > Directory Status
sets the directory "typo3conf" as being mandatory and tries to
create it. This is no longer needed in Composer mode.

Resolves: #104074
Releases: main, 12.4
Change-Id: I880ec2b7ff0be642c2673bb7110ef95f3dc125d5
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84637


Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>