Updates the monthly release status metric on initial preparation day

What does this MR do and why?

For issue Update monthly release status metric on initial... (gitlab-com/gl-infra/delivery#20024 - closed)

• Adds a step in the monthly release template during 'Initial preparation day' steps
  • Manually create a release-tools pipeline to increment the delivery_release_monthly_status metric to indicate that we are in "announced" state
• Updates the metric to signal "Announced" status (the RC tagging date is getting closer)
  • This should be the release day - 6 days
• This metric will be used to display the status of the monthly release on the delivery dashboard.
  • It would change the status from "open" (green) -> "announced" (yellow)