This ensures those programs, if invoked by shepherd (where standard
input is /dev/null), can still interact with the user if needed.
* gnu/build/file-systems.scm (check-ext2-file-system)
(check-bcachefs-file-system, check-btrfs-file-system):
(check-fat-file-system, check-jfs-file-system):
(check-f2fs-file-system, check-ntfs-file-system):
(check-xfs-file-system): Use 'system*/tty' instead of 'system*'.