grafana Memory commitment filters label_component of node-placeholder

[ryanlovett]

Bug description

The "JupyterHub Production Dashboards / Cluster Information / Memory commitment" graph was excluding pods with label_component of user-placeholder and node-placeholder. However the node-placeholder chart adds only the placeholder label. For now I manually removed "node-" from the graphana query but the label needs to be fixed. I think it makes sense for the label to be node-placeholder.

Environment & setup

• https://grafana.datahub.berkeley.edu/d/R3O4mbg7z/cluster-information?orgId=1&viewPanel=4
• node-placeholder/templates/_helpers.tpl

How to reproduce

Go to https://grafana.datahub.berkeley.edu/d/R3O4mbg7z/cluster-information?orgId=1&viewPanel=4.