fix: Tab order is inconsistent with ProfileMenu

[thebarrettlo]

🐛 Bug Report

The FluentProfileMenu component hard-codes a tabindex attribute value of 1 (see #4104), despite recommendations to only use 0 or -1.

https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes/tabindex

When the FluentProfileMenu is used in a flex box, such as in a FluentStack component, the tab order becomes noticeable. For example, if the FluentProfileMenu is placed at the end of the flex box/stack and users tab "forward", the FluentProfileMenu will be focused first.

💻 Repro or Code Sample

<FluentStack Orientation=Orientation.Horizontal HorizontalGap=16 HorizontalAlignment=HorizontalAlignment.End VerticalAlignment=VerticalAlignment.Center>

    @* This will be focused SECOND *@
    <FluentAnchor Href="https://microsoft.com")
                  title="Focusable 0"
                  Target="_blank"
                  Appearance=Appearance.Hypertext>
        Focusable 0
    </FluentAnchor>

    @* This will be focused THIRD *@
    <FluentAnchor Href="https://github.com")
                  title="Focusable 1"
                  Target="_blank"
                  Appearance=Appearance.Hypertext>
        Focusable 1
    </FluentAnchor>

    @* This will be focused FOURTH *@
    <FluentAnchor Href="https://linkedin.com")
                  title="Focusable 2"
                  Target="_blank"
                  Appearance=Appearance.Hypertext>
        Focusable 2
    </FluentAnchor>

    @* This will be focused FIRST *@
    <FluentProfileMenu HeaderLabel="Microsoft"
                       Initials="BG"
                       FullName="Bill Gates"
                       EMail="bill.gates@microsoft.com"
                       PopoverStyle="min-width: 330px;" />
</FluentStack>

🤔 Expected Behavior

FluentProfileMenu is focusable using tab but follows the visual and written order of focusable elements.

😯 Current Behavior

FluentProfileMenu is focused out of order from sibling elements--typically first.

💁 Possible Solution

Set tabindex in FluentProfileMenu to 0.

🔦 Context

Failed tab stop tests in Accessibility Insights for Web. Failures in these accessibility tests are non-compliant for Microsoft-developed UIs.

🌍 Your Environment

• OS & Device: Windows on PC
• Browser: Microsoft Edge
• .NET 9 and Fluent UI Blazor library Version 4.13.1