Bump github.com/prometheus/client_golang from 1.7.1 to 1.8.0 in /expo…

…rters/metric/prometheus (#1397)

* Bump github.com/prometheus/client_golang in /exporters/metric/prometheus

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.7.1 to 1.8.0.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/master/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.7.1...v1.8.0)

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

* Auto-fix go.sum changes in dependent modules

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: dependabot[bot] <dependabot[bot]@users.noreply.github.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>