feat: change prompts in ensemble v2

[Hoder-zyf]

Description

Since PR 1077 was incorrectly merged into main and also merged both hypo_critic and hypo_rewrite, this PR is cherry-picked from the original version.

Motivation and Context

How Has This Been Tested?

• [ ] If you are adding a new feature, test on your own test scripts.

Screenshots of Test Results (if appropriate):

1. Your own tests:

Types of changes

• [ ] Fix bugs
• [ ] Add new feature
• [ ] Update documentation

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📚 Documentation preview 📚: https://RDAgent--1107.org.readthedocs.build/en/1107/