CI: Record one result with duration (#57954)
Helps fill this out with something meaningful, which is better than the
current zero duration and the old overcounting.
https://buildkite.com/organizations/julialang/analytics/suites/julialang-base?branch=master
<img width="1046" alt="Screenshot 2025-03-30 at 11 19 20 PM"
src="https://github.com/user-attachments/assets/76e25e2d-aef8-4687-b349-c7017a7b3cdd"
/>
