Update GitHub Actions workflow to conditionally upload coverage for Python 3.12 and adjust maximum function evaluations in optimization script

Author: rogeriojorge

.github/workflows/build_test.yml

@@ -45,6 +45,7 @@ jobs:
         pytest --cov-branch --cov-report=xml --cov=essos
 
     - name: Upload coverage reports to Codecov
+      if: matrix.python-version == '3.12'
       uses: codecov/codecov-action@v5
       with:
         token: ${{ secrets.CODECOV_TOKEN }}

examples/optimize_coils_vmec_surface.py

@@ -12,7 +12,7 @@
 max_coil_curvature = 0.5
 order_Fourier_series_coils = 6
 number_coil_points = order_Fourier_series_coils*10
-maximum_function_evaluations = 500
+maximum_function_evaluations = 300
 number_coils_per_half_field_period = 4
 tolerance_optimization = 1e-5
 ntheta=32