Runner job Metrics tab now populated with in-VM machine metrics

The Metrics tab for Tuist Runners CI jobs now displays real CPU, Memory, Network, and Storage samples for each job. The runner itself collects the metrics from inside the macOS or Linux VM, so the dashboard no longer stays empty for jobs running on Tart VMs or kata microVMs. The backend accepts the runner’s own credentials and records each sample against the currently claimed job. Metrics appear once jobs run on the new runner image.