Remove blackbox-exporter

Remove blackbox-exporter from headlamp and use monitorings blackbox exporter: https://repo1.dso.mil/big-bang/product/packages/monitoring/-/blob/main/chart/charts/prometheus-blackbox-exporter-11.0.0.tgz?ref_type=heads

Remove:

• subchart deps/prometheus-blackbox-exporter
• deps in chart.yaml
• remove metrics from values.yaml
• all mention of metrics within chart/templates

Make sure that prometheus is able to see servicemonitor similar to: !38 (merged)