Fix anonymous definition

[YingboMa]

This PR fixes the following error

julia> f = @ode_def begin
         dx = a*x - b*x*y
         dy = -c*y + d*x*y
       end a b c d
#375 (generic function with 2 methods)

julia> f([0.1,0.2], [1,2], [1,2,3,4], 1)
ERROR: UndefVarError: a not defined
Stacktrace:
 [1] macro expansion at ./REPL[19]:2 [inlined]
 [2] (::getfield(Main, Symbol("##213#219")))(::Array{Float64,1}, ::Array{Int64,1}, ::Array{Int64,1}, ::Int64) at /home/scheme/.julia/dev/ParameterizedFunctions/src/ode_def_opts.jl:235
 [3] (::getfield(Main, Symbol("##375")){getfield(Main, Symbol("##213#219")),getfield(Main, Symbol("##214#220")),getfield(Main, Symbol("##215#221")),getfield(Main, Symbol("##216#222")),getfield(Main, Symbol("##217#223")),getfield(Main, Symbol("##218#224")),Expr,Expr})(::Array{Float64,1}, ::Array{Int64,1}, ::Array{Int64,1}, ::Int64) at /home/scheme/.julia/dev/ParameterizedFunctions/src/maketype.jl:82
 [4] top-level scope at none:0

[ChrisRackauckas]

merge when tests pass and we'll re-tag v3.12.0 to this commit.