[BUGFIX] EXT:saltedpasswords remove dependency on EXT:setup

As saltedpasswords is required for backend and can't be uninstalled, we
can remove the implicit dependency on extension "setup" by adjusting
the default settings there.

Resolves: #58192
Releases: 6.2
Change-Id: I6490b9962924c0e384243f663f3e5057c947749e
Reviewed-on: https://review.typo3.org/29656
Reviewed-by: Nicole Cordes
Tested-by: Nicole Cordes
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn