fix: update error code to -32022 for detecting server-supported protocol versions

Author: anubhav756

packages/toolbox-core/src/toolbox_core/mcp_transport/v20260618/mcp.py

@@ -150,7 +150,7 @@ async def _send_request(
             # Check for JSON-RPC Error
             if "error" in json_resp:
                 err_val = json_resp["error"]
-                if isinstance(err_val, dict) and err_val.get("code") == -32004:
+                if isinstance(err_val, dict) and err_val.get("code") == -32022:
                     server_supported = err_val.get("data", {}).get("supported", [])
                     client_supported = (
                         self._supported_protocols