fix(agent,env): delete prompt pk and change env paper search num

[lwaekfjlk]

Closes #

📑 Description

✅ Checks

• [ ] My pull request adheres to the code style of this project
• [ ] My code requires changes to the documentation
• [ ] I have updated the documentation as required
• [ ] All the tests have passed
• [ ] Branch name follows type/descript (e.g. feature/add-llm-agents)
• [ ] Ready for code review

ℹ Additional Information

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 86.72%. Comparing base (7a3dc81) to head (fb67ada). Report is 1 commits behind head on main.

@@            Coverage Diff             @@
##             main     #756      +/-   ##
==========================================
+ Coverage   86.69%   86.72%   +0.02%     
==========================================
  Files          62       62              
  Lines        2698     2696       -2     
==========================================
- Hits         2339     2338       -1     
+ Misses        359      358       -1     

Files with missing lines	Coverage Δ
research_town/data/data.py	100.00% <ø> (ø)
...esearch_town/envs/env_proposal_writing_with_rag.py	98.11% <100.00%> (-0.04%)	:arrow_down:
tests/configs/test_configs.py	86.95% <100.00%> (ø)

... and 1 file with indirect coverage changes