Bug: Undo returns the mark of the deleted comment

Lexical version: 0.50.0

## Steps To Reproduce

1. Add a comment to the text
2. Delete the comment thread in the right-hand panel
3. Press Ctrl + Z

## The current behavior

A state is returned containing an invalid marker that references a comment that no longer exists

https://github.com/user-attachments/assets/b973dd18-2e76-4e83-a66c-bfe34c16c41d

## The expected behavior

During Undo/Redo operations, it is necessary to either restore the deleted comment in the right-hand panel or validate the mark ID and remove it if it references a non-existent comment

## Impact of fix

The current issue creates redundant mark nodes in the state that do not reference anything. Any users basing their implementation on the `CommentPlugin` from the playground inherit this bug

Reproduce the issue through the CommentPlugin playground flow: add a comment, delete its thread from the right-hand panel, then use Ctrl+Z. Inspect the Undo/Redo state for mark IDs that reference missing comments; done means the deleted comment is restored or the invalid mark is removed, with no redundant mark nodes remaining.

Written by the indexing model from the issue text.