Add issue label guidelines for astroid-related issues

Add instructions to check GitHub issue labels and only create regression tests for astroid-related issues that cannot be fixed from this repository.

Co-authored-by: Pierre-Sassoulas <[email protected]>

Author: Copilot

.github/copilot-instructions.md

@@ -4,6 +4,15 @@ Always follow these instructions first and fallback to additional search and con
 gathering only if the information in these instructions is incomplete or found to be in
 error.
 
+## Issue Label Guidelines
+
+Before attempting to fix any issue, check the GitHub issue labels using the GitHub API:
+
+- If an issue is labeled with "Astroid", "Needs astroid update", "Needs astroid constraint", or "Needs astroid Brain 🧠", **ONLY** create regression tests
+- Do **NOT** attempt to fix astroid-related issues as you cannot modify astroid from this repository
+- For astroid-related issues, focus on creating comprehensive regression tests that reproduce the problem
+- All other issues can be fixed normally following the standard development workflow
+
 ## Development Environment Setup
 
 ### Basic Installation