Multi-Label Support for Actions Runner Controller (ARC) [GA]

### Value Prop

Multi-label support in Actions Runner Controller (ARC) gives enterprises the flexibility to manage complex workflows without duplicating infrastructure. Instead of maintaining separate scale sets for each configuration, customers can assign multiple labels. For example a single scale set could have labels that represent attributes for operating system, hardware, compliance, and network configuration. This capability simplifies runner management, reduces operational overhead, and ensures jobs land on the right compute resources with minimal effort.

### Expected Outcome

Customers gain a streamlined approach to autoscaling and job routing, improving resource utilization and reducing idle capacity. This results in lower infrastructure costs, faster execution, and better alignment with compliance and performance requirements, delivering an efficient and scalable self-hosted runner experience.