profile-icons with web sources are not shown on the taskbar

### Windows Terminal version (or Windows build number)

1.8.1521.0

### Other Software

_No response_

### Steps to reproduce

**I am using WINDOWS 11, I do not know how this behaves in Win10.**

1. Create a new profile (or use an existing one)
2. For the icon, paste a weblink to an ico file (eg https://github.com/favicon.ico)
3. As you will see, that works fine (the icon gets shown in new tabs and in the settings menu)
4. keep winterm open
5. right-click onto the program in the taskbar
6. As you will see, the icons are not rendered here

### Expected Behavior

Profile Icons are rendered the same way everywhere across the device

### Actual Behavior

Profile Icons from the web are not rendered at all in the taskbar dialog

No source file, test, or entry point is named. Reproduce the issue on Windows 11 with Windows Terminal 1.8.1521.0 using a profile icon linked to an ICO file, then trace the taskbar rendering path. Done means web-hosted profile icons render in the taskbar dialog as they do in tabs and settings.

Written by the indexing model from the issue text.