tests: Disable tap for shell scripts that only invoke the test scripts

tests: Disable tap for shell scripts that only invoke the test scripts

In successful test runs there is the following line in some cases

    # Looks like your test died before it could output anything

This happens due the test script's util.sh automatically "starting"
the TAP state; however, in these cases the actual tap output is
produced by other scripts or binaries.

Change-Id: Iad8f74b0fc1b0a998eba3171d7a2626cd3e86824
Signed-off-by: Kienan Stewart <kstewart@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>