Remove/update prometheus payload for metric removals

What does this MR do and why?

Helps in moving #397138 (closed) forward with metric removals.

This MR removes/updates the prometheus payload by removing metrics_dashboard_url and related code.

Screenshots or screen recordings

NA

How to set up and validate locally

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #397138 (closed)