[TASk] Remove dummy files from ext:saltedpasswords

Change-Id: I41a31d60e2038f0677548e01cec93942818b06ed
Resolves: #47800
Related: #47756
Releases: 6.2
Reviewed-on: https://review.typo3.org/20394
Reviewed-by: Alexander Opitz
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Felix Kopp
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn