Bug in untested branch causes SymbolicAWEModels.jl to fail

[ufechner7]

Failure in running the tests of SymbolicAWEModels.jl:

 (sam.sys_struct.wings[1]).heading = 0.0
  [QUATERNION] No forces: wing_drift=0.002m, kcu_drift=0.002m, speed=0.002m/s
┌ Warning: Apparent wind too small for VSM linearization (va_b=[9.47265843177539e-11, 0.0, 3.204487827237707e-11]), skipping wing 1
└ @ SymbolicAWEModels ~/work/SymbolicAWEModels.jl/SymbolicAWEModels.jl/src/linearize.jl:77
  [QUATERNION] Gravity: z: 17.32 → 5.38m
Wind+gravity stable: Error During Test at /Users/runner/work/SymbolicAWEModels.jl/SymbolicAWEModels.jl/test/test_wing.jl:205
  Got exception outside of a @test
  ArgumentError: body_aero.va is undefined after set_va! with distributed inflow. Use panel.va or solver.sol._va_dist for per-panel inflow data.
  Stacktrace:
    [1] getproperty
      @ ~/.julia/packages/VortexStepMethod/acNLN/src/body_aerodynamics.jl:121 [inlined]
    [2] linearize(solver::VortexStepMethod.Solver{10, 3}, body_aero::VortexStepMethod.BodyAerodynamics{10, Wing{10}}, y::Vector{Float64}; theta_idxs::UnitRange{Int64}, delta_idxs::Nothing, va_idxs::UnitRange{Int64}, omega_idxs::UnitRange{Int64}, aero_coeffs::Bool, kwargs::@Kwargs{moment_frac::Float64})
      @ VortexStepMethod ~/.julia/packages/VortexStepMethod/acNLN/src/solver.jl:1047
    [3] update_vsm!(sam::SymbolicAWEModel{SystemStructure{VSMWing}, SymbolicAWEModels.SerializedModel{Vector{Pair{Symbolics.Num, Any}}, Vector{Pair{Symbolics.Num, Any}}}}, prob::SymbolicAWEModels.ProbWithAttributes{SciMLBase.ODEProblem{Vector{Float64}, Tuple{Float64, Float64}, true, ModelingToolkitBase.MTKParameters{Vector{Float64}, Vector{Float64}, Tuple{}, Tuple{Vector{Float64}}, Tuple{Vector{SystemStructure{VSMWing}}}, Tuple{}}, SciMLBase.ODEFunction{true, SciMLBase.AutoSpecialize, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0x4f7c8dc5, 0x56184eb9, 0x8e589eb5, 0x60d06bc6, 0x62bf5570), Nothing}, RuntimeGeneratedFunctions.RuntimeG