Self-Hosted Runner Peak Concurrency Visibility for Administrators [GA]

### Value Prop
Administrators can now easily see the highest number of self-hosted runner jobs running at the same time across their organization or enterprise, all in one place. This helps teams understand their usage and estimate future costs before new pricing takes effect.

### Expected Outcome
By providing clear visibility into peak self-hosted runner concurrency, admins can confidently plan budgets, avoid surprise charges, and ensure a smooth transition to the upcoming pricing model. This change empowers organizations to make informed decisions and manage their GitHub Actions resources more effectively.