Posisble for Redis/Valkey Instance state cache to get out of sync with platform

### Current Behavior

If Forge application shuts down while an instance is being suspended it is possible for the entry in the cache to get stuck in the `suspending` state.

### Expected Behavior

Transient states should expire and be checked against the underlying platform.

### Steps To Reproduce

- Start and instance
- Suspend an instance
- before it completes kill the forge app

### Environment

- FlowFuse version: 2.28.0
- Node.js version: 20
- npm version: 10.x
- Platform/OS: k8s
- Browser: all

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate