[TASK] Streamline `SchemaMigratorTest` of `EXT:core`

The SchemaMigratorTest currently works on a fully
populated database, which makes the tests more
brittle than they should be.

The patch uses a preparation in testing-framework
to let TF create a database, but not populate it
with tables, which stabilizes the tests.

> composer u typo3/testing-framework

Resolves: #104256
Releases: main
Change-Id: I6699d0e4e831bc72468afd453a83886133e124b2
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84942


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