Breaking: #82296 - Removed constant TYPO3_user_agent

See forge#82296

Description

The unused PHP constant TYPO3_user_agent containing information of the User Agent string sent for requests by TYPO3, has been removed.

Impact

Calling the constant will result in a PHP fatal error.

Affected Installations

TYPO3 installations with third-party extensions that make use of the PHP constant.

Migration

The extension scanner checks if the constant is used.

Any extension authors are encouraged to use php:$GLOBALS['TYPO3_CONF_VARS']['HTTP']['headers']['User-Agent'] instead.