Update Dispose pattern rule to handle DisposeAsync pattern

[Evangelink]

public async ValueTask DisposeAsync()
{
    await DisposeAsyncCore().ConfigureAwait(false);
    Dispose(false);
    GC.SuppressFinalize(this);
}

protected virtual ValueTask DisposeAsyncCore()
{
    // Async version of code inside `if (disposing)` blocks from Dispose(bool)
}

Originally posted by @bartonjs in #3679 (comment)

[Eli-Black-Work]

Any update on this? Just ran into this again today.