Breaking: #77826 - RTEHtmlArea Spellchecker eID removed

See Issue #77826

Description

The RTEHtmlArea eID (rtehtmlarea_spellchecker) for using dynamic spellchecking has been removed.

RTEhtmlarea uses the Backend Routing API for Backend and Frontend Editing.

Impact

Calling the eID script will result in a 404 error.

Affected Installations

Installations which use the eID rtehtmlarea_spellchecker in a custom extension.