fix: handle non-vector non-symbolic array u0 for ODEProblem

Author: AayushSabharwal

src/systems/diffeqs/abstractodesystem.jl

@@ -812,7 +812,7 @@ function process_DEProblem(constructor, sys::AbstractODESystem, u0map, parammap;
     end
 
     if eltype(u0map) <: Number
-        u0map = unknowns(sys) .=> u0map
+        u0map = unknowns(sys) .=> vec(u0map)
     end
     if u0map === nothing || isempty(u0map)
         u0map = Dict()