fix: adapt the new openApi structure

Author: jokemanfire

crates/rmcp/tests/test_complex_schema.rs

@@ -45,7 +45,11 @@ fn test_complex_schema() {
     let attr = Demo::chat_tool_attr();
     let input_schema = attr.input_schema;
     let enum_number = input_schema
-        .get("definitions")
+        .get("components")
+        .unwrap()
+        .as_object()
+        .unwrap()
+        .get("schemas")
         .unwrap()
         .as_object()
         .unwrap()