SyncShapesToTablesOptions onInitialSync type should allow async

```
export interface SyncShapesToTablesOptions {
key: string | null
shapes: Record
useCopy?: boolean // DEPRECATED: use initialInsertMethod instead
initialInsertMethod?: InitialInsertMethod
onInitialSync?: () => void | Promise
}
```

I think this would be better to show async support? It would also follow the example given in linear-lite