Update tests/test_mcp_protocol.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: chefgs

tests/test_mcp_protocol.py

@@ -83,7 +83,6 @@ def __init__(self) -> None:
             cwd=_REPO_ROOT,
         )
         self._next_id = 1
-        self._handshake_done = False
 
     # ------------------------------------------------------------------
     # Low-level transport helpers