Fix misleading docstring in _unregister_toolgroup_async

[coderabbitai]

Summary

The docstring for _unregister_toolgroup_async in tests/e2e/utils/llama_stack_utils.py is misleading. It says:

"Unregister a toolgroup by identifier; return (provider_id, provider_shield_id) for restore."

However, the function signature is -> None and the implementation only ever returns None. This docstring appears to have been copied from _unregister_shield_async, which does return restoration data.

Suggested Fix

 async def _unregister_toolgroup_async(identifier: str) -> None:
-    """Unregister a toolgroup by identifier; return (provider_id, provider_shield_id) for restore."""
+    """Unregister a toolgroup by identifier."""
     client = _get_llama_stack_client()

References

• PR: LCORE-1329: Adding new MCP E2E Tests #1327
• Review comment: LCORE-1329: Adding new MCP E2E Tests #1327 (comment)

Requested by @tisnik.