Support older Linux systems

[Yxure]

The current version of the plugin is compiled using GLIBC 2.38, which only works on recent versions of Linux. GLIBC is a critical component of Linux systems, and updating it is complicated and can break the system. The Godot editor faces the same issue and solves it by compiling on an older distribution (see this issue godotengine/godot#31950).

[pkdawson]

The latest release (v6.3.2) should be built with glibc-2.35. Is that old enough, or is there a reason you need something earlier?

I generally expect people playing/developing games on Linux to be using a recent distro, but I dunno what version of glibc SteamOS has, for example.

[Yxure]

I hadn't realized the addon had been updated. I tested the new version on my system, which uses glibc 2.35, and it works perfectly. So from my side, there wouldn't be any issue.

[Luminoth]

@Yxure did you have to do anything else when you tested the new version? I've tried both the AssetLib version and the direct addon but I'm still getting this error:

System.Runtime.InteropServices.NativeLibrary.Load(string): System.DllNotFoundException: Unable to load shared library '{project path}/.godot/mono/temp/bin/Debug/runtimes/linux-x64/native/libcimgui.so' or one of its dependencies. In order to help diagnose loading problems, consider using a tool like strace. If you're using glibc, consider setting the LD_DEBUG environment variable: 
/lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.38' not found (required by {project path}/.godot/mono/temp/bin/Debug/runtimes/linux-x64/native/libcimgui.so)

I'm not even sure right now if that's the plugin itself or if it's actually ImGUI.Net that's the issue.

EDIT - oh, ok looks like it actually is ImGUI.NET from ImGuiNET/ImGui.NET#491 (comment). I'll dig around there to see if they've solved that end of it.

EDIT - using polyfill-glibc from ImGuiNET/ImGui.NET#491 (comment) got me fixed up