Disable unit checking of initialization problem during remake

This is the default during problem construction (problem_utils.jl:1305).
Partial fix for #3283.

Author: contradict

src/systems/nonlinear/initializesystem.jl

@@ -660,7 +660,7 @@ function SciMLBase.remake_initialization_data(
     kws = maybe_build_initialization_problem(
         sys, SciMLBase.isinplace(odefn), op, t0, defs, guesses,
         missing_unknowns; time_dependent_init, use_scc, initialization_eqs, floatT,
-        u0_constructor, p_constructor, allow_incomplete = true)
+        u0_constructor, p_constructor, allow_incomplete = true, check_units=false)
 
     odefn = remake(odefn; kws...)
     return SciMLBase.remake_initialization_data(sys, odefn, newu0, t0, newp, newu0, newp)

test/initializationsystem.jl

@@ -1105,6 +1105,10 @@ end
         guesses = ModelingToolkit.missing_variable_defaults(pend))
     sol = solve(prob, Rodas5P())
     @test SciMLBase.successful_retcode(sol)
+
+    prob2 = remake(prob, u0=[x => 0.5, y=>nothing])
+    sol2 = solve(prob2, Rodas5P())
+    @test SciMLBase.successful_retcode(sol2)
 end
 
 @testset "Issue#3205" begin