Handle truncation properly with PPO

[vwxyzjn]

Description

This PR is a prototype for #198 and https://github.com/sail-sg/envpool/issues/194

Types of changes

• [ ] Bug fix
• [x] New feature
• [ ] New algorithm
• [ ] Documentation

Checklist:

• [ ] I've read the CONTRIBUTION guide (required).
• [ ] I have ensured pre-commit run --all-files passes (required).
• [ ] I have updated the documentation and previewed the changes via mkdocs serve.
• [ ] I have updated the tests accordingly (if applicable).

If you are adding new algorithms or your change could result in performance difference, you may need to (re-)run tracked experiments. See https://github.com/vwxyzjn/cleanrl/pull/137 as an example PR.

• [ ] I have contacted vwxyzjn to obtain access to the openrlbenchmark W&B team (required).
• [ ] I have tracked applicable experiments in openrlbenchmark/cleanrl with --capture-video flag toggled on (required).
• [ ] I have added additional documentation and previewed the changes via mkdocs serve.
  • [ ] I have explained note-worthy implementation details.
  • [ ] I have explained the logged metrics.
  • [ ] I have added links to the original paper and related papers (if applicable).
  • [ ] I have added links to the PR related to the algorithm.
  • [ ] I have created a table comparing my results against those from reputable sources (i.e., the original paper or other reference implementation).
  • [ ] I have added the learning curves (in PNG format with width=500 and height=300).
  • [ ] I have added links to the tracked experiments.
  • [ ] I have updated the overview sections at the docs and the repo
• [ ] I have updated the tests accordingly (if applicable).

[vercel[bot]]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Updated
cleanrl	✅ Ready (Inspect)	Visit Preview	Nov 12, 2022 at 1:55AM (UTC)

[vwxyzjn]

Due to the lack of performance improvement, temporarily closing this PR.

[KaleabTessera]

Shouldn't this use terminal_observation to handle trunc correctly?