LightGBM v4 support

[painhardcore]

Currently
only version=v3 is supported
v4 was released a while ago https://github.com/microsoft/LightGBM/releases/tag/v4.0.0
Latest version is v4.4 https://github.com/microsoft/LightGBM/releases/tag/v4.4.0

[biorisk]

My company has released an MIT-licensed library for using lightgbm v4 by way of purego rather than cgo. It might be an alternative. Depending on your use case, it might have some rough edges.

[painhardcore]

Hi @biorisk, thank you for your suggestion, but I'm looking for Go only lib without CGO or linking to something external.

[lp1985621]

golightly does not support batch predictions @painhardcore

[AnyCPU]

if someone needs a support of the v4, chances are changing following code block is enough. Similar ad-hoc solution is also applied in original repo.

you should add a code block for the "v4" string.

I guess it will be nice if some tests are added.