Fix performance test

[dweindl]

• more narrow timing of simulations
• reduce tolerance

Closes #3145.

👀 https://github.com/dweindl/AMICI/actions/runs/22620944043

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.72%. Comparing base (8d42dcb) to head (71686c3).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3149      +/-   ##
==========================================
- Coverage   77.36%   76.72%   -0.64%     
==========================================
  Files         317      317              
  Lines       20628    20628              
  Branches     1483     1483              
==========================================
- Hits        15958    15826     -132     
- Misses       4662     4794     +132     
  Partials        8        8              

Flag	Coverage Δ
cpp	70.44% <ø> (ø)
cpp_python	37.14% <ø> (ø)
petab	47.16% <ø> (ø)
python	68.90% <ø> (ø)
sbmlsuite-jax	?

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see 4 files with indirect coverage changes

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