Keyboard focus moves to "Installation Successfully Completed" text after close button but focus indicator is not visible.: A11y_ .NET SDK and CLI_InstallationScreen_Keyboard

### Github Tags:
#A11yTCS; #A11yMAS; #WCAG2.4.3; #A11ySev3; #ScreeReader; #E2E_.NET SDK and CLI_Win32_Jul2026; #DesktopApp; #FTP; #.NET SDK and CLI; #FocusOrder; #a11ydb-static-in-tab-order;

### Issue Subcategory:
A few static elements are in the tab order

### User Experience:
Keyboard users encounter a few unnecessary tab stops on non-interactive content, which adds minor effort to reach the actual controls but does not break navigation

### Repro Steps:
Open .net sdk preview> Installation screen>Install>Installation Successfully Completed > Observed the issue.

### Actual Result:
After pressing TAB on the Close button, keyboard focus moves to the "Installation Successfully Completed" text. However, the text does not have a visible focus indicator, making it impossible for keyboard users to determine where focus has landed.

### Expected Result:
Keyboard focus should move only to interactive elements, or if focus lands on an element, a visible focus indicator must be provided so users can identify the current focus location.

### How to Fix:
Remove `tabindex="0"` from non-interactive elements so only interactive controls are in the tab order; if an element must be programmatically focusable for focus management, use `tabindex="-1"` so it stays out of the default tab sequence of the interface

### Environment details:
Application Name: .NET SDK and CLI
OS: Windows 11 Enterprise Insider Preview 26300.8276

### Note:
"Contact [CAI Accessibility Support Channel](https://teams.microsoft.com/l/channel/19:DeCtYeREyQHw5jYsz9PPc3hpVw48m-tOlTkQ1jEn0eM1%40thread.tacv2/CAI%20Accessibility%20Support%20Channel?groupId=f5eb428c-9e6e-4c16-8143-33fe3961a9ae&tenantId=72f988bf-86f1-41af-91ab-2d7cd011db47) for Accessibility queries on design, development, test, usability or any processes"
Check out Accessibility Insights! - Identify accessibility bugs before check-in and make bug fixing faster and easier.

### Attachment:

https://github.com/user-attachments/assets/26f8674d-1760-4df2-ac96-8e77b31cf354