[TASK] Do not use SiteFinder to fetch Site in Frontend

TSFE now always contains the Site object so it is not necessary to
use the SiteFinder based on the ID to fetch the correct Site anymore,
but use TSFE->getSite() directly.

Resolves: #93654
Releases: master
Change-Id: I2ddd6b0409f73edc4f6fa8f6c7bb0ab21d567272
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/68188


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Richard Haeser <richard@richardhaeser.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Richard Haeser <richard@richardhaeser.com>