fix python builtin

Author: aldehir

common/chat.cpp

@@ -1363,7 +1363,7 @@ static void common_chat_parse_gpt_oss(common_chat_msg_parser & builder) {
         "functions\\.([a-zA-Z_][a-zA-Z0-9_]*)\\s?(?:<\\|constrain\\|>([a-zA-Z]+))?<\\|message\\|>"
     );
     static const common_regex browser_tool_call_regex("browser\\.(search|open|find)[\\s\\S]*<\\|message\\|>");
-    static const common_regex python_tool_call_regex("python\\s?(?:<|constrain|>code)?<\\|message\\|>");
+    static const common_regex python_tool_call_regex("python\\s?(?:code)?<\\|message\\|>");
 
     auto consume_until_start = [&]() {
         if (auto res = builder.try_find_regex(start_regex, std::string::npos, false)) {