[KeyboardManager][Known issue] Icon not appearing in title bar and task bar

### Microsoft PowerToys version

0.98.0

### Installation method

Other (please specify in "Steps to Reproduce")

### Area(s) with issue?

Keyboard Manager

### Steps to reproduce

Icon not appear in task bar or title bar.
1. Run PowerToys
2. Launch the new KBM UI
3. Observe missing Icons

### ✔️ Expected Behavior

Icons should appear

### ❌ Actual Behavior

Icons do not appear, this is a known issue with WinUI 3 tracked here: https://github.com/microsoft/WinUI-Gallery/issues/1512

### Upload Bug Report ZIP-file

_No response_

### Additional Information

### Other Software

_No response_

Start by reproducing the missing icons in the new Keyboard Manager UI using the listed steps, then read the linked WinUI 3 issue for the current status and applicable guidance. Done means the Keyboard Manager icons appear in the title bar and task bar, or the issue is updated with the confirmed upstream limitation and resolution path.

Written by the indexing model from the issue text.