Allow compiled binaries to get version

[Hofer-Julian]

We started using the function that Julia provides, but it doesn't seem to work with compiled binaries

Fixes #364

[deltamarnix]

I did a test on the Main branch and I checked main_test.jl.

I changed the test to

@testitem "version" begin
    using IOCapture: capture

    (; value, output) = capture() do
        Ribasim.main(["--version"])
    end
    @test value == 0
    @test output != "nothing"
    @test VersionNumber(output) > v"0.0.0"
end

It works locally, but as described in the issue, the binary .exe returns "nothing".
The solution provided in this PR breaks this adjusted test in code mode, but will make the binary.exe return correct values.

I would suggest to make a bug report that shows these differences with an example: https://github.com/JuliaLang/julia/issues

[deltamarnix]

I don't know how the Ribasim team is on this, but to have less nesting you could write it as: !isnothing(version) && return version

[Hofer-Julian]

Fine by me