fix: Pre-selected values cannot be deleted from FluentAutocomplete

[MarvinKlein1508]

🐛 Bug Report

When you have a predefined value assigned to a bound property of a FluentAutocomplete it cannot be deleted unless you have selected another value.

This used to work in 4.10.2 but it does not in 4.10.3

💻 Repro or Code Sample

I've created a small sample repository which can be found here:
https://github.com/MarvinKlein1508/FluentUI-Autocomplete-issue

🤔 Expected Behavior

You should be able to delete the predefined value, just like it in 4.10.2.

😯 Current Behavior

The value can only be deleted whenever you select another value first.

[MarvinKlein1508]

When I remove the added if block here everything works for me just like before.

fluentui-blazor/src/Core/Components/List/ListComponentBase.razor.cs

Line 539 in 78ff71e

if (_selectedOptions.Count != 0)

[MarvinKlein1508]

Or alternativly:

if (_selectedOptions.Count != 0 || SelectedOptions?.Any() == true)

[dvoituron]

See #2891