Replace prometheus remote write endpoint

[aly]

Summary

Replace the Grafana cloud remote write endpoint with the new self-hosted Prometheus remote write endpoint.

Proposed Solution

Configuration update: prometheus/prometheus.yml

Update remote write endpoint

https://prometheus-prod-10-prod-us-central-0.grafana.net/api/prom/push
to
https://vm.monitoring.gcp.obol.tech/write

remote_write:
 - url: https://prometheus-prod-10-prod-us-central-0.grafana.net/api/prom/push
  authorization:
   credentials: 436764:$PROM_REMOTE_WRITE_TOKEN

remote_write:
 - url: https://vm.monitoring.gcp.obol.tech/write
  authorization:
   credentials: $PROM_REMOTE_WRITE_TOKEN

Add cluster name/Id under the global config section:

global:
 external_labels:
  clusterid: charon-123

Describe alternatives you've considered

N/A

Out of Scope

N/A