async: effects don't run when a prop is awaited

### Describe the bug

When awaiting a component prop in the template, effects in the component don't run directly.
Mutating a state will run them.
Might be related to #16497

### Reproduction

https://svelte.dev/playground/43ca8ba4ec294b05ad1fb42789e61433?version=5.39.4

### Logs

```shell

```

### System Info

```shell
Svelte 5.39.4
```

### Severity

blocking an upgrade