Conditional CI resource management

Configure CI workflows to intelligently manage system resources through conditional execution rather than duplicating steps. Use matrix variables or job conditions to determine when resource-intensive operations should run.

For resource monitoring tasks (like disk usage checks), define a condition that prevents redundant execution:

- name: print disk usage
  # Only run this step if the free_disk operation isn't executed
  if: $
  run: |
    echo "disk usage:"
    df -h

When configuring runners, explicitly document resource constraints and set appropriate flags that control resource management steps:

runners:
  - &job-windows
    os: windows-2025
    free_disk: true  # Explicitly mark jobs that need disk space freed
    <<: *base-job

This approach keeps workflows maintainable by avoiding duplicative steps, makes resource constraints visible, and ensures consistent behavior across different execution environments.