[dev-v5] fix: `@bind-xxx:after` is being executed twice in `FluentAutocomplete`

[MarvinKlein1508]

🐛 Bug Report

The @bind-SelectedItems:after and @bind-SelectedItem:after callbacks are executed twice in FluentAutocomplete when you select an item.

💻 Repro or Code Sample

<div>
    Current count: <span data-testid="current-value">@countAfter</span>
</div>

<FluentAutocomplete TValue="string"
                    TOption="string"
                    Label="Test"
                    Items="Options"
                    @bind-SelectedItems="SelectedItems"
                    @bind-SelectedItems:after="AfterChanged" />

@code
{
    string test = string.Empty;
    int countAfter = 0;
    IEnumerable<string> SelectedItems { get; set; } = [];

    void AfterChanged()
    {
        countAfter++;
    }

    List<string> Options = new List<string>
    {
        "Option 1",
        "Option 2",
        "Option 3",
        "Option 4",
        "Option 5"
    };
}

1. Run the code
2. Click on the component
3. Select an item
4. See count is 2 instead of 1

🤔 Expected Behavior

I expect the method to be executed once.

😯 Current Behavior

I expect the method will be executed twice.

💁 Possible Solution

🔦 Context

I created this PR with an integration test for this case #4753

For some reason if you try to validate it in the normal unit tests the count will always be 1.

🌍 Your Environment

• OS & Device: Windows 11 64 Bit
• Browser latest Firefox Chrome & Edge
• latest dev-v5 branch