Breaking: #61802 - deprecated isLocalconfWritable function removed

See forge#61802

Description

The function isLocalconfWritable() from \TYPO3\CMS\Core\Utility\ExtensionManagementUtility has been removed. The bootstrap now just checks for the existence of the file and redirects to the install tool if it doesn't exist.

Impact

Extensions that still use the function isLocalconfWritable() won't work.

Affected installations

A TYPO3 instance is affected if a 3rd party extension uses the removed function.

Migration

Remove the call to this function. The bootstrap takes care to check the existence of the file.