[TASK] Remove leftover TSFE factory method

Since the removal of the container entry, the
factory method
TypoScriptFrontendController->getGlobalInstance() is
obsolete.

Resolves: #96338
Related: #96273
Releases: main
Change-Id: Ib8c973acb240cac0c7f18c10fbc801585b7c70b7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/72635


Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>