[Copilot] Edge case around broken symlinks

[roderik]

• Copilot Chat Extension Version: Latest stable and insiders (14 aug)
• VS Code Version: Latest stable and insiders (14 aug)
• OS Version: macos
• Feature (e.g. agent/edit/ask mode): Send button
• Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): all of them

Steps to Reproduce:

1. Create a symlink from .github/copilot-instructions.md to a non exisiting file
2. Try to send a message in the chat panel

No errors but it does not do anything Remove the symlink, and all works fine.

I guess it should be fairly easy to ignore these broken links and not fail