Function when

when(
condition: (context: BackoffContext) => boolean,
strategy: BackoffStrategy,
): BackoffStrategy
Conditional backoff - only retry if condition is met
Parameters
- condition: (context: BackoffContext) => boolean
- strategy: BackoffStrategy
Returns BackoffStrategy
Example
```
// Only retry on specific errors
agenda.define('myJob', handler, {
  backoff: when(
    (ctx) => ctx.error.message.includes('timeout'),
    exponential({ delay: 1000, maxRetries: 3 })
  )
});
```
- Defined in utils/backoff.ts:193