ci: Use honeycomb to trace builds

Created by: jhchabran

This PR integrates honeycomb's buildevents in our pipeline, enabling us to trace build and to get an overview of the timings. It goes down to the command level.

Associated infra PR: https://github.com/sourcegraph/infrastructure/pull/2997

Dashboard preview

Trace preview

Annoatation preview

TODO:

• Draft a dashboard on Honeycomb
• Send events from a PR
• Send events from a PR with the full main dry run (including E2E agents).
• Extract the buildevents binary from the post-checkout hook to avoid downloading it everytime.
• Merge the infra PR and deploy the new agents