[TASK] Initialize FormProtectionFactory later in alt_doc.php

The FormProtectionFactory can be initialized later.
Move the initialization to the point where it is needed.

Resolves: #55856
Releases: 6.2
Change-Id: Id83304341ddec4cc2d4d5c8a6bd40463277a37b5
Reviewed-on: https://review.typo3.org/27533
Reviewed-by: Benjamin Mack
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel