[BUGFIX] Fix checkbox items in "Global Configuration" card

Resolve duplicated `class` declaration which prevented
the element from being recognized by the JavaScript
endpoint.

Add missing `form-check-label-text` class for the checkbox
label text.

Remove invalid `p` tags from checkbox elements description.

Resolves: #93929
Releases: master
Change-Id: Ice0fdd1646f27dd8d98f33c8453cfa8ae2ce3b79
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/68777


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>