[DOCS] Fix ImageUpload YAML code

Releases: main, 11.5
Resolves: #97436
Change-Id: I341d8650a5411f3c102948a3f659194574d97749
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74363


Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>