use NoSchedule taint data in system information in metrics report rather than reporting it repeatedly

[dklyle]

The system config data in the json files already contains the NoSchedule taint information. This information does not change during a test run. Use the system config information rather than repeatedly reporting the NoSchedule taint per node, per iteration. This will avoid unnecessary overhead of making execs to the stats pods.

[dklyle]

I'm actually inclined to leave this as is for the k8s_scale.sh, it's fixed in k8s_scale_rapid.sh, but the node information is used in the k8s_scale.sh as well. While it would be possible to extract it. I'm not sure the overall benefit is worth it at this point.