[TASK] Drop obsolete todos from MM table generator

Database columns 'sorting' and 'sorting_foreign' for
MM relation tables are hard coded and not a valid TCA
configuration option since a long time. Drop two
recently added todo's to clearify this.

Resolves: #95232
Releases: master
Change-Id: I8f874bd2f08eebadc81c5f3a46afbd0970e603c4
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71096


Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>