[BUGFIX] Allow utf8mb3 as well for CharsetToCheck

On recent MariaDB versions >= 10.6 utf8 is an alias for utf8mb3 while
until MariaDB 10.5 utf8mb3 was an alias for utf8.

https://mariadb.com/kb/en/unicode/



Resolves: #101719
Releases: main, 12.4, 11.5
Change-Id: Ida8a5b89fd99f9ff196d496ddb34d55c9657daf5
Reviewed-by: Timo Gurr <timo.gurr@gmail.com>
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80616


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Timo Gurr <timo.gurr@gmail.com>