Bump github.com/prometheus/alertmanager from 0.24.0 to 0.25.1

Bumps [github.com/prometheus/alertmanager](https://github.com/prometheus/alertmanager) from 0.24.0 to 0.25.1.
- [Release notes](https://github.com/prometheus/alertmanager/releases)
- [Changelog](https://github.com/prometheus/alertmanager/blob/v0.25.1/CHANGELOG.md)
- [Commits](https://github.com/prometheus/alertmanager/compare/v0.24.0...v0.25.1)

---
updated-dependencies:
- dependency-name: github.com/prometheus/alertmanager
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f