[DOCS] Remove all highlight directives from dashboard docs

These directives are currently causing errors in opening rst
files in PHP storm.

Also it is best practice to only use explicit code blocks or
literalincludes.

Resolves: #104848
Releases: main, 12.4
Change-Id: I1271b6e4f5e032a1f0d5835e141334e263b30169
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/85916


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