Retrieving InvalidOperationException when inserting new item to collection

### Describe the bug

First of all, I'm using the [JsonFlatFileDataStore ](https://github.com/ttu/json-flatfile-datastore) package.

I'm trying to insert a new item to a collection and the insertion works, but the `CommunityToolkit.Mvvm.dll` throws a `System.InvalidOperationException`.

```csharp
// THIS IS DEFINED IN A SEPARATE ClassLibrary targeting NET 6 with JsonFlatFileDataStore installed
public async Task CreateReference(ReferenceObject reference)
{
if (!_service.IsDataServiceInitialized())
return -1;
// Get ReferenceObject collection
var collection = _service.DataStore!.GetCollection();
try
{
bool result = await collection.InsertOneAsync(reference); // HERE IS WHERE THE ERROR IS THROWN
if (result)
return reference.Id;
}
catch (Exception ex)
{

throw;
}
return -1;
}
```

The message to call the previous class is:

```csharp
public async void Receive(AddReferenceMessage message)
{
var newId = await _referenceManager.CreateReference(message.Value);

message.Value.SetNewId(newId);

ReferenceCollection.Add(message.Value);

message.Reply(newId);
}
```

(`AddReferenceMessage` inherits from `AsyncRequestMessage`)

I'm using a custom AsyncCommand class where I pass the `IMessenger` in the constructor to call the message:

```csharp
...
try
{
int newId = await _messenger.Send(new AddReferenceMessage(viewModel._reference));

_messenger.Send(new ShowMainSnackBarMessage($"Successfully added reference {viewModel.Name}"));

_viewModel.LoadReferencesCommand.Execute(null);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message); // HERE I CATCH THE ERROR
}

...
```

### Regression

_No response_

### Steps to reproduce

```text
Environment:
NET 6
CommunityToolkit.Mvvm 8.1
JsonFlatFileDataStore 2.4.1
```

### Expected behavior

To retrieve correctly the new id of the inserted object, as the object is properly inserted into the JSON file and a new id is assigned to the new object.

### Screenshots

_No response_

### IDE and version

VS 2022

### IDE version

_No response_

### Nuget packages

- [ ] CommunityToolkit.Common
- [ ] CommunityToolkit.Diagnostics
- [ ] CommunityToolkit.HighPerformance
- [X] CommunityToolkit.Mvvm (aka MVVM Toolkit)

### Nuget package version(s)

8.1.0

### Additional context

_No response_

### Help us help you

Yes, but only if others can assist