[TASK] Remove dummy files from ext:linkvalidator

Change-Id: Idecc7408ddd0a799c0e239f2585ee993b7293fc6
Resolves: #47833
Related: #47756
Releases: 6.2
Reviewed-on: https://review.typo3.org/20417
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn