Breaking: #98343 - Removed TYPO3 v12 support 

Description 

Support for TYPO3 v12 has been removed for 6.x based on our dual TYPO3 core version support per major version as casual support matrix.

This includes removing code paths and configurations only required for TYPO3 v12.

Impact 

TYPO3 v12 or older instances cannot update to the 6.x version and are required to upgrade TYPO3 to be able to install the next version of the EXT:deepltranslate_core and related extensions/addons based on this version.

Extension cannot be installed in that version but does not break otherwise.

Affected installations 

TYPO3 v12 or older instances with EXT:deepltranslate_core version 5.x.

Migration 

Upgrade TYPO3 to supported version for 6.x beforehand or in the same step.