Deprecation: #65344 - typo3conf/extTables.php deprecated

See Issue #65344

Description

The file typo3conf/extTables.php which could be used for local TCA modifications has been marked as deprecated.

Setting $GLOBALS['TYPO3_CONF_VARS']['DB']['extTablesDefinitionScript'] together with the constant TYPO3_extTableDef_script are deprecated and should not be used any longer.

Impact

The options and files are typically used for "poor man" $GLOBALS['TCA'] overrides. This is discouraged and shouldn't be used any longer.

Migration

There are two options to migrate away from typo3conf/extTables.php usage, the first one should be preferred:

• It is good practice to have a project / site specific extension that contains templates, TypoScript and other stuff. Create one or more dedicated extensions and use TCA overrides to apply the desired modifications. Something like $GLOBALS['TCA']['pages']['ctrl']['hideAtCopy'] = FALSE; should be moved from typo3conf/extTables.php to typo3conf/ext/<your_extension>/Configuration/TCA/Overrides/pages.php.
• Slot the signal tcaIsBeingBuilt that is emitted in ExtensionManagementUtility.php.