Update pymc.sample docstring to fix incorrect property name

[treszkai]

Fix typo in idata.sample_stats

Description

Property name idata.sample_stats in the docs was incorrect.

Related Issue

• Closes #
• Related to #

Checklist

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

Type of change

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

---

📚 Documentation preview 📚: https://pymc--7321.org.readthedocs.build/en/7321/

[twiecki]

Thanks!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.48%. Comparing base (b59a9eb) to head (536755f).
Report is 143 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7321   +/-   ##
=======================================
  Coverage   92.48%   92.48%           
=======================================
  Files         102      102           
  Lines       17129    17129           
=======================================
  Hits        15842    15842           
  Misses       1287     1287           

Files	Coverage Δ
pymc/sampling/mcmc.py	87.74% <ø> (ø)