Fix a typo in the docstring for OrderedLogistic

[NathanielF]

Fixing a Docstring Example

Just a tiny change to fix a docstring for the orderedlogit class, the current docstring fails to run. This resolves it.
Related to discussion here

Checklist

• Explain important implementation details 👆
• Make sure that the pre-commit linting/style checks pass.
• Link relevant issues (preferably in nice commit messages)
• Are the changes covered by tests and docstrings?
• Fill out the short summary sections 👇

Major / Breaking Changes

• NA

New features

• NA

Bugfixes

• NA

Documentation

• Changed docstring

Maintenance

• NA

[codecov]

Codecov Report

Merging #6611 (7110bd3) into main (c7279b5) will decrease coverage by 30.89%.
The diff coverage is n/a.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #6611       +/-   ##
===========================================
- Coverage   87.09%   56.21%   -30.89%     
===========================================
  Files          93       93               
  Lines       15737    15737               
===========================================
- Hits        13706     8846     -4860     
- Misses       2031     6891     +4860     

Impacted Files	Coverage Δ
pymc/distributions/discrete.py	50.63% <ø> (-48.09%)	⬇️

... and 72 files with indirect coverage changes

[ricardoV94]

Thanks @NathanielF