Breaking: #77481 - Remove favicon from TBE_STYLES 

See forge#77481

Description 

The configuration $GLOBALS['TBE_STYLES']['favicon'] has been removed.

Impact 

The configuration $GLOBALS['TBE_STYLES']['favicon'] is not evaluated anymore.

Affected Installations 

Any installation using $GLOBALS['TBE_STYLES']['favicon'].

Migration 

Define the favicon in the setting of EXT:backend in the extension manager.