fix: FluentWizard can navigate to disabled last step using default buttons

[Hwiet]

🐛 Bug Report

When no ButtonTemplate is provided and the last step of the wizard is disabled, the user is able to navigate to the last step using the default buttons.

💻 Repro or Code Sample

<FluentWizard>
    <Steps>
        <FluentWizardStep>
            Content 1
        </FluentWizardStep>

        <FluentWizardStep>
            Content 2
        </FluentWizardStep>

        <FluentWizardStep Disabled="true">
            Content 3
        </FluentWizardStep>
    </Steps>
</FluentWizard>

msedge_lbEqGUJGsT.mp4

🤔 Expected Behavior

In the above reproduction, the "Done" button should appear on step 2 instead of step 3.

😯 Current Behavior

The "Next" button appears on step 2 and clicking on it causes the wizard to navigate to the disabled last step.

🌍 Your Environment

• OS & Device: Windows 11 on PC
• Browser: Microsoft Edge
• .NET 8.0.7 and Fluent UI Blazor 4.9.3

[dvoituron]

That's right. Thank you for finding this problem.

[dvoituron]

Fixed in next Release #2503