Fix docs deploy job by installing mkdocstrings dependencies

[Copilot]

Summary

The deploy GitHub Actions job failed during mkdocs gh-deploy because mkdocs.yml enables mkdocstrings, but the workflow only installed mkdocs-material. This PR aligns workflow dependencies with the configured MkDocs plugins.

• Root cause

  • .github/workflows/docs.yml installed only mkdocs-material, while mkdocs.yml requires:
    • mkdocstrings
    • mkdocstrings-python

• Change

  • Updated the docs deploy install step to include required plugins.

• Patch

  - run: pip install mkdocs-material
  + run: pip install mkdocs-material mkdocstrings mkdocstrings-python

Checklist

• Tests added or updated
• Docs updated (docstrings, README, or tutorial as appropriate)
• Linting passes (ruff check .)
• For new environments: IPPO results on 20 seeds included