[BUGFIX] Fix unlinking of anchors to hidden or deleted pages in RTE

When RTE content is loaded from database the attribute `data-rte-error`
is added to the markup when the linked record is hidden or deleted.

The Typo3UnlinkCommand needs to remove this data attribute in order for
CKEditor to remove the surrounding `<a>`.

Resolves: #107620
Releases: main, 13.4
Change-Id: I8443989cd8ed05cb3a1616216a7822c1a6de8f51
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/90938
Tested-by: Garvin Hicking <garvin@hick.ing>
Reviewed-by: Garvin Hicking <garvin@hick.ing>
Tested-by: Benjamin Franzke <ben@bnf.dev>
Reviewed-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Andreas Nedbal <andy@pixelde.su>
Reviewed-by: Andreas Nedbal <andy@pixelde.su>

Author: bnf

Build/Sources/TypeScript/rte-ckeditor/plugin/typo3-link.ts

@@ -254,6 +254,7 @@ export class Typo3UnlinkCommand extends Core.Command {
         writer.removeAttribute('linkTarget', range);
         writer.removeAttribute('linkTitle', range);
         writer.removeAttribute('linkRel', range);
+        writer.removeAttribute('linkDataRteError', range);
       }
     });
   }