Breaking: #61782 - deprecated DocumentTemplate classes removed 

See forge#61782

Description 

The following deprecated classes have been removed:

TYPO3CMSBackendTemplateMediumDocumentTemplate TYPO3CMSBackendTemplateSmallDocumentTemplate TYPO3CMSBackendTemplateStandardDocumentTemplate

Impact 

Extensions that still use one of the removed classes for their backend module won't work.

Affected installations 

A TYPO3 instance is affected if a 3rd party extension uses one of the removed classes.

Migration 

Use TYPO3CMSBackendTemplateDocumentTemplate instead.