Deprecation: #77934 - Deprecate tt_content field select_key

See Issue #77934

Description

The field select_key of the table tt_content is not used in the core and has been removed.

Impact

The field select_key is not available by default anymore.

Affected Installations

All installations and extensions using the field select_key of the table tt_content.

Migration

Install the extension compatibility7 to enable the field again.