Add luvit-meta

luvit-meta is available in [24.11](https://search.nixos.org/packages?channel=24.11&show=vimPlugins.luvit-meta&from=0&size=50&sort=relevance&type=packages&query=luvit-meta) and [unstable](https://search.nixos.org/packages?channel=unstable&show=vimPlugins.luvit-meta&from=0&size=50&sort=relevance&type=packages&query=luvit-meta) https://github.com/JMartJonesy/kickstart.nixvim/blob/185ec7c4c8627350431dd5b09455140b0cd9cf62/plugins/lsp.nix#L23 https://github.com/JMartJonesy/kickstart.nixvim/blob/185ec7c4c8627350431dd5b09455140b0cd9cf62/plugins/lsp.nix#L3-L4