Snackbar Presenter throws an error when it is unloaded.

Describe the bug

Hello

Hello, I've identified a bug during my use of the Snackbar presenter. I haven't fully understood why yet, but when I navigate from one page to another with a Snackbar presenter, an error is thrown because of this event handler: System.ObjectDisposedException: 'The CancellationTokenSource has been disposed.'

After some research, it might be due to this:
protected virtual void OnUnloaded()
{
CancellationTokenSource.Cancel();
CancellationTokenSource.Dispose();
}

So, I created a new class inheriting from the Snackbar presenter but overriding this event handler, and the error no longer appears.

To Reproduce

Steps to recreate the bug:

1. Create a Page A without Snackbar Presenter.
2. Create a Page B with Snackbar Presenter.

Once the app is launched:
3. Navigate to Page B.
4. Return to Page A.
5. Then navigate again to Page B.

Expected behavior

Correct this x)

Screenshots

No response

OS version

Windows 11

.NET version

8.0

WPF-UI NuGet version

3.0

Additional context

No response

Start with the Snackbar presenter and inspect the protected OnUnloaded method shown in the report, then reproduce the Page A → Page B → Page A → Page B navigation sequence on Windows with .NET 8. Done means navigating away from and back to the page no longer throws the CancellationTokenSource ObjectDisposedException.