fix calculation of bulk ocp in hysteresis models

[rtimms]

Description

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context.

Fixes # (issue)

Type of change

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Important checks:

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• No style issues: nox -s pre-commit
• All tests pass: nox -s tests
• The documentation builds: nox -s doctests
• Code is commented for hard-to-understand areas
• Tests added that prove fix is effective or that feature works

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.87%. Comparing base (6618fe1) to head (fa6a9ba).
⚠️ Report is 97 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5169      +/-   ##
===========================================
- Coverage    98.88%   98.87%   -0.01%     
===========================================
  Files          320      320              
  Lines        26875    26872       -3     
===========================================
- Hits         26574    26571       -3     
  Misses         301      301              

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[aabills]

looks like a few forgotten print statements, otherwise looks good.