[TASK] Remove runThroughTemplatesPostProcessing hook

Hook call runThroughTemplatesPostProcessing related to the
old TypoScript parser is now removed in the new TypoScript
parser: This hook has been marked as breaking in 12.0
already and was only kept for b/w compat in
typo3/testing-framework, which has been adapted meanwhile.

The substitution event AfterTemplatesHaveBeenDeterminedEvent
is slightly changed to provide the full Request to listeners
instead of just the Site object.

> composer u typo3/testing-framework

Change-Id: I0b46aa50c576782f6853f91105478cd66d0ddcc3
Resolves: #98550
Related: #97816
Releases: main
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75995


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>