Deprecation: #89742 - Form mixins 

See forge#89742

Description 

All mixins in the "form" extension have been deprecated and should not be used anymore. This affects all inheritances from TYPO3.CMS.Form.mixins.*.

The mixins have been deprecated with TYPO3v10 and will be removed with TYPO3v11.

Impact 

Form setup inheriting mixins from TYPO3.CMS.Form.mixins.* will trigger a deprecation warning in TYPO3v10.

With TYPO3v11 these mixins will be removed which will lead to an error.

Affected Installations 

Instances using the "form" extension and inheriting from TYPO3.CMS.Form.mixins.* in their form setup.

Migration 

Embed the essential parts from TYPO3.CMS.Form.mixins.* or migrate them to custom mixins.