fix(server_mcp): read Tool.input_schema for mcp 2.3.0 (#3522)

mcp==2.3.0 Tool stores the JSON Schema on input_schema (alias
inputSchema). Accessing tool.inputSchema raises AttributeError and
aborts server_mcp init after a successful tools/list.

Use getattr fallback so function-calling conversion works.

Closes #3521

Co-authored-by: shinjiyu <shinjiyu@users.noreply.github.com>

main/xiaozhi-server/core/providers/tools/server_mcp/mcp_client.py

@@ -107,7 +107,7 @@ class ServerMCPClient:
                 "function": {
                     "name": name,
                     "description": tool.description,
-                    "parameters": tool.inputSchema,
+                    "parameters": getattr(tool, "input_schema", None) or getattr(tool, "inputSchema", {}),
                 },
             }
             for name, tool in self.tools_dict.items()