Merge branch 'sy-setup-http-integrations-for-prometheus' into 'master'

Add support for Prometheus as HTTP alert integrations

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/120046



Merged-by: Roy Zwambag <rzwambag@gitlab.com>
Approved-by: Tianwen Chen <tchen@gitlab.com>
Approved-by: João Alexandre Cunha <j.a.cunha@gmail.com>
Reviewed-by: João Alexandre Cunha <j.a.cunha@gmail.com>
Reviewed-by: Sarah Yasonik <syasonik@gitlab.com>
Reviewed-by: Roy Zwambag <rzwambag@gitlab.com>
Reviewed-by: Tianwen Chen <tchen@gitlab.com>
Co-authored-by: syasonik <syasonik@gitlab.com>