Fix missing function parameter in search.py

[amoor22]

Description

This PR fixes a bug in the _reduce_response function in the search.py file in global_search.

A format call is made on the self.reduce_system_prompt string which contains a placeholder for max_length which is not provided in the format call.

Proposed Changes

Add the missing parameter to the function call.

Checklist

• [ x ] I have tested these changes locally.
• [ x ] I have reviewed the code changes.
• [ x ] I have updated the documentation (if necessary).
• [ x ] I have added appropriate unit tests (if applicable).