Breaking: #101398 - Remove leftover $fetchAllFields in RelationHandler

See forge#101398

Description

The TYPO3\CMS\Core\Database\RelationHandler had an unused property $fetchAllFields since TYPO3 11.5.0. The related method setFetchAllFields has been removed with it.

Impact

Custom extensions calling TYPO3\CMS\Core\Database\RelationHandler->setFetchAllFields will result in a PHP Fatal error.

Affected installations

All installations with custom extensions calling TYPO3\CMS\Core\Database\RelationHandler->setFetchAllFields.

Migration

Remove the affected line of code. This method has had no effect since TYPO3 11.5.0.