[TASK] Remove dummy files from ext:dbal

Change-Id: I62715d95f7453aa0e86dddc299aba4dc9cbe19d1
Resolves: #47838
Related: #47756
Related: #47836
Releases: 6.2
Reviewed-on: https://review.typo3.org/20423
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn