[TASK] Remove unused DH $data_disableFields

Similar to #103132. This time, public `@internal`
property $data_disableFields is only read, but
never written.

Reading the property comment, it looks as if this
may have been used as a detail scenario within
ext:impexp that has been removed long ago.

History reveals no core usage since ever: That
property hasn't even been used with Kaspers
initial commit in 2003.

Let's drop this artifact and keep it in versioning
museum forever.

Resolves: #103133
Related: #103132
Releases: main
Change-Id: I2bfddad06f2cbb2610fb55f67a9dda40d75ab7e8
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83016


Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>