[BUGFIX] Ensure database connection port is integer

It's possible the port is provided as a string. This has to be taken
care for before handed over to doctrine/dbal as it is strictly typed
and doesn't do type casting on its own.

Resolves: #102918
Related: #102875
Releases: main
Change-Id: Ib2f65611e6fc924e00387ba27811dc07e3bae598
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/82637


Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>