Add eq_fixed option to BoundaryError

[IssraAli]

An option to remove the equilibrium as an optimizable DOF when computing BoundaryError is included.

[github-actions]

Memory benchmark result

|               Test Name                |      %Δ      |    Master (MB)     |      PR (MB)       |    Δ (MB)    |    Time PR (s)     |  Time Master (s)   |
| -------------------------------------- | ------------ | ------------------ | ------------------ | ------------ | ------------------ | ------------------ |
  test_objective_jac_w7x                 |   -3.44 %    |     4.095e+03      |     3.954e+03      |   -140.99    |       30.35        |       28.94        |
  test_proximal_jac_w7x_with_eq_update   |   -0.58 %    |     6.619e+03      |     6.580e+03      |    -38.25    |       152.79       |       151.46       |
  test_proximal_freeb_jac                |   -0.58 %    |     1.342e+04      |     1.335e+04      |    -77.54    |       79.34        |       79.13        |
  test_proximal_freeb_jac_blocked        |    0.03 %    |     7.726e+03      |     7.728e+03      |     2.27     |       68.99        |       69.00        |
  test_proximal_freeb_jac_batched        |    0.11 %    |     7.653e+03      |     7.661e+03      |     8.25     |       68.70        |       69.11        |
  test_proximal_jac_ripple               |    1.52 %    |     3.536e+03      |     3.589e+03      |    53.74     |       52.56        |       52.14        |
  test_proximal_jac_ripple_bounce1d      |    0.36 %    |     3.720e+03      |     3.733e+03      |    13.50     |       66.94        |       65.82        |
  test_eq_solve                          |    0.10 %    |     1.929e+03      |     1.931e+03      |     1.93     |       57.99        |       58.00        |

For the memory plots, go to the summary of Memory Benchmarks workflow and download the artifact.

[codecov]

Codecov Report

❌ Patch coverage is 85.71429% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 94.30%. Comparing base (7b6ed16) to head (87c4602).
⚠️ Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
desc/objectives/_free_boundary.py	85.71%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2264      +/-   ##
==========================================
- Coverage   94.30%   94.30%   -0.01%     
==========================================
  Files         101      101              
  Lines       28866    28901      +35     
==========================================
+ Hits        27223    27255      +32     
- Misses       1643     1646       +3     

Files with missing lines	Coverage Δ
desc/objectives/_free_boundary.py	94.93% <85.71%> (-1.54%)	⬇️

... and 3 files with indirect coverage changes

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[YigitElma]

You can also add a test like test_toroidal_flux to check all paths run fine.

[YigitElma]

I think the reason tests are failing is that constants["field"] is a SumMagneticField and it expects a list for the params. So, the parameter assignment needs a bit more care. For this objective, field can be something like [MixedCoilSet(), ToroidalMagneticField()].

[YigitElma]

About the formatting and linting check, if you run the following, they will happen automatically everytime you commit something.

pip install pre-commit
pre-commit install

These and some other useful instructions can be found on the Contributing Guide.

[YigitElma]

Note to other devs: The failing test is related to jax-finufft version 1.2.0 and not caused by this PR. We should solve that problem separetaly or wait CI to run that test on a different python version (which doesn't install jax-finufft 1.2.0)