Fix pre-equilibration error with generate_sensitivity_code=False

[dweindl]

Only call Model::initializeStateSensitivities if we are computing sensitivities. Fixes a recently introduced bug that results in a simulation error when running pre-equilibration with models that were imported with generate_sensitivity_code=False.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.99%. Comparing base (ddf9b72) to head (4989fc2).
⚠️ Report is 50 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2924      +/-   ##
==========================================
- Coverage   79.58%   78.99%   -0.59%     
==========================================
  Files         362      362              
  Lines       23128    23130       +2     
  Branches     1587     1588       +1     
==========================================
- Hits        18406    18272     -134     
- Misses       4711     4847     +136     
  Partials       11       11              

Flag	Coverage Δ
cpp	74.92% <100.00%> (-0.02%)	⬇️
cpp_python	33.17% <100.00%> (+<0.01%)	⬆️
petab	38.84% <66.66%> (+<0.01%)	⬆️
python	73.77% <66.66%> (-0.03%)	⬇️
sbmlsuite-jax	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/forwardproblem.cpp	90.38% <100.00%> (+0.03%)	⬆️

... and 7 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.