Bump the prometheus group across 1 directory with 2 updates (#6690)

* Bump the prometheus group across 1 directory with 2 updates

Bumps the prometheus group with 2 updates in the / directory: [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) and [github.com/prometheus/common](https://github.com/prometheus/common).


Updates `github.com/prometheus/client_golang` from 1.19.1 to 1.20.4
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.19.1...v1.20.4)

Updates `github.com/prometheus/common` from 0.55.0 to 0.59.1
- [Release notes](https://github.com/prometheus/common/releases)
- [Changelog](https://github.com/prometheus/common/blob/main/RELEASE.md)
- [Commits](prometheus/common@v0.55.0...v0.59.1)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: prometheus
- dependency-name: github.com/prometheus/common
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: prometheus
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update metrics doc

Signed-off-by: Antonin Bas <antonin.bas@broadcom.com>

---------

Signed-off-by: dependabot[bot] <support@github.com>
Signed-off-by: Antonin Bas <antonin.bas@broadcom.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Antonin Bas <antonin.bas@broadcom.com>