Don't add Go plugin in LaziVim Extras when Go is not installed

[roelandxyz]

Support for Go is added in the LazyVim Extras:
https://github.com/basecamp/omakub/blob/master/configs/neovim/lazyvim.json

But that only works when Go is installed. When Go is not selected for installation, you will get an error that gopls can not be installed.
Neovim still works. You just get an error popup for a couple of seconds.

This is easy to fix after installation. Install Go with Omakub or remove the extra in LazyVim.

Is a change needed in Omakub for this? Only add the extra plugin if Go is selected for installation?

[Kasui92]

Here's a PR (#269) that solves that problem and only installs neovim plugin for the selected languages.