Revert documentation paths in `Sampler` submodule

[HumphreyYang]

This PR fixes the path for API entries of Sampler submodule.

Description

Change the .. currentmodule:: attribute to the old path prior to v.5.10.1. The order of entries is maintained as it is for minimal changes.

Documentation after changes are applied:

Related Issue

• [x] Closes #7070

Checklist

• [x] Checked that the pre-commit linting/style checks pass
• [x] Included tests that prove the fix is effective or that the new feature works
• [x] Added necessary documentation (docstrings and/or example notebooks)
• [x] If you are a pro: each commit corresponds to a relevant logical change

Type of change

• [ ] New feature / enhancement
• [ ] Bug fix
• [x] Documentation
• [ ] Maintenance
• [ ] Other (please specify):

---

📚 Documentation preview 📚: https://pymc--7072.org.readthedocs.build/en/7072/

[welcome[bot]]

:sparkling_heart: Thanks for opening this pull request! :sparkling_heart: The PyMC community really appreciates your time and effort to contribute to the project. Please make sure you have read our Contributing Guidelines and filled in our pull request template to the best of your ability.