Breaking: #81950 - Remove leftover workspaces unpublishing functionality
See forge#81950
Description
A property within workspaces for "unpublishing" published records has been disabled since TYPO3 4.5.
This functionality allowed to restore a published workspace which was published at a given time, to revert the changes on another time, but had side-effects if changes were made between publishing and unpublishing.
However, this functionality was not visible to TYPO3 out of the box, but only available with a possible third-party integration since TYPO3 4.5. The feature was therefore removed from TYPO3 Core.
The (hidden) database field sys_ was removed.
Impact
Using the functionality will not work anymore, operating on the database with this field will result in a SQL error.
Affected Installations
Any installation using the workspace functionality with automatic publishing and a third-party extension for unpublishing.
Migration
If this feature is required for an installation, the field should be re-added by the third-party extension in TCA (which was missing) and the database which was using the functionality. On top, a custom auto-unpublishing CLI command should be created.