[DOCS] Use proper yaml quoting in MakeRefreshable.rst

Invalid char encoding has slipped into an yaml
example snippet for ext:dashboard. This change
use the correct quoting to fix this.

Releases: main, 12.4, 11.5
Resolves: #102319
Change-Id: I3dd2fd7a1aec51ad3f1ace7c6b914371e9e12342
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/81657


Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>