vim9 support

[dmorilha]

First of all congrats on the plug-in, is a great achivement! so much ligheter than YCM and trivial to set-up. vim9 was just released with a new and allegendly fast scripting language, are you planning to update? Would you accept a PR?

[xaizek]

I'm not sure Vim9 will improve performance by much, python and libclang do most of the work anyway. You can give it a try and measure, however using Vim9 will probably make the plugin unusable with NeoVim, so it might not be worth it unless the gain is substantial.