[BUG] Exception when closing the picker before it has had time to load the assets

[LeGoffMael]

Describe the bug
Reproducible on the current example application.
When the picker is closed before it has had time to load the assets, an exception is thrown.

[VERBOSE-2:dart_vm_initializer.cc(41)] Unhandled Exception: A DefaultAssetPickerProvider was used after being disposed.
Once you have called dispose() on a DefaultAssetPickerProvider, it can no longer be used.
#0      ChangeNotifier.debugAssertNotDisposed.<anonymous closure>
change_notifier.dart:179
#1      ChangeNotifier.debugAssertNotDisposed
change_notifier.dart:186
#2      ChangeNotifier.notifyListeners
change_notifier.dart:382
#3      DefaultAssetPickerProvider.getAssetsFromPath.run
asset_picker_provider.dart:374
<asynchronous suspension>

How to reproduce

Steps to reproduce the behavior:

1. Run the example app
2. Click on 'Common Picker'
3. Close it immediately after opening
4. Error occurred.

Expected behavior
There should be no exceptions.

Screenshots (If contains)

RPReplay_Final1694591427.mov

Version information

• Device: iPhone 11 pro
• OS: iOS 16.2
• Package Version: 8.7.1
• Flutter Version: 3.13.3