[DOCS] Properly refer to DatePicker prototype API

The API code snippet is related to 'DatePicker'
and not to 'AdvancedPassword', probably due to
a copy&paste mistake.

Releases: main, 12.4, 11.5
Resolves: #105207
Change-Id: Icb57f4f053c8ce86e093bcdfd0f836145c692602
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/86474


Tested-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Garvin Hicking <gh@faktor-e.de>