[PATCH] tests/start-stop-agent: use 'command -v' instead of 'which'

[Jeffrey Walton]

On Mon, Aug 15, 2022 at 4:04 PM Sam James via Gnupg-devel
<gnupg-devel at lists.gnupg.org> wrote:
>
> `which` is an external command which isn't required by POSIX.
>
> Debian and other distributions (like Gentoo!) are looking
> to drop it from their base set of packages.
>
> Switch to `command -v` which should always work instead.
>
> Note we already use `command -v` at the start of this test anyway.

+1. `command -v` is Posix, and it properly handles things like user
environments and shell aliases.

Jeff