` radius_beam_tangency` and `radius_beam_tangency_max` are calculated but values not passed to data stucture

[grmtrkngtn]

Describe the bug

In build.py, the function calculate_beam_port_size() is called, and it returns radius_beam_tangency and radius_beam_tangency_max, but these are never passed to the data structure, and in the output files have value zero. This also means constraint 20 is broken in current implementation of PROCESS...

This is the fix:, l35 build.py

current_drive_variables.radius_beam_tangency, current_drive_variables.radius_beam_tangency_max=self.calculate_beam_port_size( f_radius_beam_tangency_rmajor=current_drive_variables.f_radius_beam_tangency_rmajor, rmajor=physics_variables.rmajor, n_tf_coils=tfcoil_variables.n_tf_coils, dx_tf_inboard_out_toroidal=tfcoil_variables.dx_tf_inboard_out_toroidal, dr_tf_outboard=build_variables.dr_tf_outboard, r_tf_outboard_mid=build_variables.r_tf_outboard_mid, dx_beam_duct=current_drive_variables.dx_beam_duct, dx_beam_shield=current_drive_variables.dx_beam_shield, )

[clmould]

@grmtrkngtn I think this may be a duplicate of the issue fixed in #4037 ? I may be wrong though!