PR to increase default value of terminationDelay from 30 seconds to 4 hours.

Rationale:
terminationDelay is tied to gang termination semantics, which are meant to prevent large amounts of resources from staying reserved when a system is non-functional (e.g., when minAvailable is breached). The delay provides a grace period for the system to heal before triggering termination.

The current default of 30 seconds is too short and often disruptive. Kubernetes users are accustomed to workloads continually trying to self-heal, so shutting things down after 30 seconds is jarring. In practice, we’ve also seen inference workloads terminate before they had time to fully initialize—especially when models are large. This usually stems from user or application error: worker pods mark themselves as Ready before the model has actually finished loading, either because startup probes are not configured or because the inference framework itself signals readiness too early, before completing all initialization.

Nevertheless, we want terminationDelay and gang termination semantics to stay out of the user’s way by default. The goal is for users to be deliberate about opting in and explicitly deciding how long a workload should be given to self-heal before being considered irreparably broken. By raising the default to 4 hours, we provide enough time for workloads with heavy initialization—such as loading very large models like DeepSeek-R1—to complete without being prematurely torn down. At the same time, the system will still eventually terminate if it remains in a broken state for an extended period, preserving the original intent of gang termination.