Merge branch 'stdio_mcp_passing_env_from_adk_state' of https://github.com/pandasanjay/adk-python into stdio_mcp_passing_env_from_adk_state

Author: pandasanjay

src/google/adk/tools/mcp_tool/mcp_session_manager.py

@@ -214,8 +214,6 @@ def update_connection_params(
     # Note: We don't close sessions here to avoid blocking,
     # they will be cleaned up when detected as disconnected
 
-    # Lock to prevent race conditions in session creation
-    self._session_lock = asyncio.Lock()
 
   def _generate_session_key(
       self, merged_headers: Optional[Dict[str, str]] = None