Auto merge of #125771 - Kobzol:ci-datadog-metrics, r=jdno

[CI] Upload average CPU utilization of CI jobs to DataDog

This PR adds a new CI step that uploads the average CPU utilization of the current GH job to Datadog. I want to add more metrics in follow-up PRs.

r? `@jdno`

try-job: dist-i686-msvc
try-job: aarch64-apple
try-job: x86_64-gnu-llvm-18

Author: bors