Cache not deleted after stalePeriod is passed

## 🐛 Bug Report

I am implementing a CustomCachemanager with a `stalePeriod` of 1 minute to check if the cached data are deleted after the stale period passes. So far, it doesn't work and I don't know why. Any suggestion is welcome.

### Expected behavior

The cached data are deleted after 1 minute.

### Reproduction steps

1. Created a CustomCacheManager

import 'package:flutter_cache_manager/flutter_cache_manager.dart';

```
class CustomCacheManager extends CacheManager with ImageCacheManager {
factory CustomCacheManager() {
return _instance;
}

CustomCacheManager._()
: super(Config(key, stalePeriod: const Duration(minutes: 1)));
static const key = 'libCachedImageData';

static final CustomCacheManager _instance = CustomCacheManager._();
}
```

2. Passed it in the CachedNetworkImage Constructor.

```
CachedNetworkImage(
imageUrl: imageUrl,
fit: BoxFit.cover,
cacheManager: CustomCacheManager(),
);
```

3. Ran the app, the image is loaded from the network as it should.
4. Terminate the app.
5. re-ran the app and the image is loaded from the cache as it should
6. Terminate the app and wait for some time (i.e.: 10 mins)
7. Launch the app. At this point, I expect the image to be fetched from the network again since the cache should be deleted. Instead, the image is still fetched from the cache.

I used the flag `CachedNetworkImage.logLevel = CacheManagerLogLevel.verbose;`

Am I missing something here?

### Configuration

**Version:** 3.3.1

**Platform:**
- Android 14