Breaking: #86492 - Removed stdWrap support for config.additionalHeaders 

See forge#86492

Description 

The feature to use stdWrap for config.additionalHeaders has been removed due to an incompatibility with page caching.

Impact 

stdWrap cannot be used anymore to manipulate additional headers set via TypoScript.

Affected Installations 

Any TYPO3 instance that uses this feature, which has been introduced with version 9.0.

Migration 

For the time being there will be no TypoScript based solution for dynamic HTTP headers.

Consider implementing a PSR-15 middleware to add advanced logic for additional frontend response headers.