build-tools/test-recursively: Silence the $has_target check
build-tools/test-recursively: Silence the $has_target check

It is okay for the `$has_target` check to fail, but we are not interested in its
output, so redirect it to /dev/null.

Signed-off-by: Gergely Nagy <6780fac3b38619ac20422286e4110a70dbba2203@madhouse-project.org>

keyboardio/Arduino