fix bug in QuasisymmetryBoozer.dim_f

[ddudt]

Hot fix for a bug introduced by #1197.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.44%. Comparing base (9096947) to head (3efd119).
Report is 3 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1285      +/-   ##
==========================================
- Coverage   95.45%   95.44%   -0.02%     
==========================================
  Files          96       96              
  Lines       23791    23791              
==========================================
- Hits        22710    22707       -3     
- Misses       1081     1084       +3     

Files with missing lines	Coverage Δ
desc/objectives/_omnigenity.py	96.30% <100.00%> (ø)

... and 1 file with indirect coverage changes

[github-actions]

|             benchmark_name             |         dt(%)          |         dt(s)          |        t_new(s)        |        t_old(s)        | 
| -------------------------------------- | ---------------------- | ---------------------- | ---------------------- | ---------------------- |
 test_build_transform_fft_lowres         |     -1.17 +/- 3.38     | -6.94e-03 +/- 2.00e-02 |  5.86e-01 +/- 1.3e-02  |  5.93e-01 +/- 1.5e-02  |
 test_equilibrium_init_medres            |     -1.45 +/- 3.66     | -6.71e-02 +/- 1.70e-01 |  4.57e+00 +/- 1.3e-01  |  4.64e+00 +/- 1.1e-01  |
 test_equilibrium_init_highres           |     -1.32 +/- 3.46     | -7.93e-02 +/- 2.07e-01 |  5.91e+00 +/- 1.7e-01  |  5.99e+00 +/- 1.2e-01  |
 test_objective_compile_dshape_current   |     -2.93 +/- 1.87     | -1.22e-01 +/- 7.79e-02 |  4.04e+00 +/- 5.6e-02  |  4.16e+00 +/- 5.4e-02  |
 test_objective_compute_dshape_current   |     -5.49 +/- 4.72     | -2.09e-04 +/- 1.80e-04 |  3.60e-03 +/- 5.7e-05  |  3.81e-03 +/- 1.7e-04  |
 test_objective_jac_dshape_current       |     -1.63 +/- 5.61     | -6.95e-04 +/- 2.39e-03 |  4.20e-02 +/- 1.0e-03  |  4.27e-02 +/- 2.2e-03  |
 test_perturb_2                          |     -0.80 +/- 3.43     | -1.52e-01 +/- 6.53e-01 |  1.89e+01 +/- 4.1e-01  |  1.90e+01 +/- 5.0e-01  |
 test_proximal_freeb_jac                 |     +1.47 +/- 4.85     | +1.15e-01 +/- 3.80e-01 |  7.95e+00 +/- 3.2e-01  |  7.83e+00 +/- 2.1e-01  |
 test_solve_fixed_iter                   |     +0.73 +/- 60.80    | +3.82e-02 +/- 3.17e+00 |  5.25e+00 +/- 2.3e+00  |  5.21e+00 +/- 2.2e+00  |
 test_build_transform_fft_midres         |    +10.01 +/- 6.80     | +6.11e-02 +/- 4.15e-02 |  6.72e-01 +/- 1.1e-02  |  6.11e-01 +/- 4.0e-02  |
 test_build_transform_fft_highres        |     +4.63 +/- 2.64     | +4.66e-02 +/- 2.66e-02 |  1.05e+00 +/- 1.9e-02  |  1.01e+00 +/- 1.9e-02  |
 test_equilibrium_init_lowres            |    +11.39 +/- 6.18     | +4.38e-01 +/- 2.37e-01 |  4.28e+00 +/- 2.4e-01  |  3.84e+00 +/- 2.5e-02  |
 test_objective_compile_atf              |     -2.31 +/- 3.20     | -1.85e-01 +/- 2.56e-01 |  7.82e+00 +/- 1.7e-01  |  8.00e+00 +/- 1.9e-01  |
 test_objective_compute_atf              |     +3.37 +/- 2.44     | +3.54e-04 +/- 2.56e-04 |  1.09e-02 +/- 2.2e-04  |  1.05e-02 +/- 1.3e-04  |
 test_objective_jac_atf                  |     -0.57 +/- 3.13     | -1.14e-02 +/- 6.20e-02 |  1.97e+00 +/- 4.6e-02  |  1.98e+00 +/- 4.1e-02  |
 test_perturb_1                          |     -4.59 +/- 4.09     | -6.18e-01 +/- 5.50e-01 |  1.28e+01 +/- 4.9e-01  |  1.35e+01 +/- 2.5e-01  |
 test_proximal_jac_atf                   |     -0.61 +/- 1.21     | -5.04e-02 +/- 9.90e-02 |  8.17e+00 +/- 6.0e-02  |  8.22e+00 +/- 7.9e-02  |
 test_proximal_freeb_compute             |     +0.52 +/- 0.86     | +9.51e-04 +/- 1.59e-03 |  1.84e-01 +/- 1.2e-03  |  1.83e-01 +/- 9.9e-04  |