Issue with `julia_pull()`

[edwardlavender]

julia_pull() does not work if you define object = ... in the function.

I.e., this works:

> julia_cmd("x = 1")
> julia_pull("x")
[1] 1

This does not work:

> julia_pull("x = 1")
Error: Error happens in Julia.
MethodError: no method matching typeof(; x::Int64)
This method does not support all of the given keyword arguments (and may not support any).
Stacktrace:
 [1] top-level scope
   @ none:1
 [2] eval(m::Module, e::Any)
   @ Core ./boot.jl:489
 [3] eval_string(x::String)
   @ Main.JuliaCall /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/library/JuliaCall/julia/setup.jl:203
 [4] docall(call1::Ptr{Nothing})
   @ Main.JuliaCall /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/library/JuliaCall/julia/setup.jl:0

This is because julia_class() gets called on x = 1 not x.

This behaviour should be documented or revised.