test/system: add debug for healthcheck flake

Seen it a few times, the exit code differs but we didn't print the
command output so it hard to tell why podman errors out here.
This just adds the output and does not fix the flake.

https://api.cirrus-ci.com/v1/artifact/task/5368521426731008/html/sys-podman-fedora-41-rootless-host-boltdb.log.html

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

test/system/220-healthcheck.bats

@@ -439,6 +439,7 @@ function _check_health_log {
     # Wait for background healthcheck to finish and make sure the exit status is 1
     rc=0
     wait -n $hc_pid || rc=$?
+    cat $hcStatus # just as debug in case the exit code check fails
     assert $rc -eq 1 "exit status check of healthcheck command"
     assert $(< $hcStatus) == "stopped" "Health status"