Handling prompts with different placeholder names

[gordon-lim]

# main/examples/llm_prompt_optimization/evaluate_prompts.py

        try:
            formatted_prompt = prompt_template.format(instruction=instruction)
        except KeyError:
            # Handle prompts with different placeholder names
            formatted_prompt = prompt_template.replace("{instruction}", instruction)

The fallback doesn't seem to handle the KeyError. If there's a key error wouldn't it mean that the prompt_template does not contain "{instruction}".

[codelion]

Yeah, it ideally shouldn't reach this point as in my experiments the generated prompts by the LLM always used the same placeholder, I will fix it to just fail and return 0.