Automerge: [CI] Extend metrics container to log BuildKite metrics (#129699)

The current container focuses on Github metrics. Before deprecating
BuildKite, we want to make sure the new infra quality is better, or at
least the same.

Being able to compare buildkite metrics with github metrics on grafana
will allow us to easily present the comparison.

This PR requires llvm/llvm-zorg#400 to be merged
first.

Author: Keenuts