All four of these scripts have #! lines calling for them to run in bash,
and they are all marked as executable, so there's no harm in running them
directly and it makes it clearer that we're running them in the shell
specified on the #! line, rather than with whatever "sh' happens to be
on the current system.

(Note that this _was_ still correctly using the #! lines before, because
it's `sh -c` rather than just `sh`, but nonetheless that old way seemed
needlessly confusing.)