[!!!][TASK] Remove config.htmlTag TypoScript properties

The two TypoScript options

* config.htmlTag_langKey
* config.htmlTag_dir

have been removed, as they have no effect anymore in TYPO3 v10,
which only works with Site Handling.

Site Handlings "direction" and "twoLetterIsoCode" are already
in place and used when Site Handling is active.

Resolves: #88560
Releases: master
Change-Id: I8ef2a8b8ccd9c790fd7db940e908e8a362ec4ca3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61003


Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Benni Mack <benni@typo3.org>