lsp: replace rnix-lsp with nil

user/home.nix

@@ -122,7 +122,6 @@
     nodePackages.typescript-language-server
     flow # js lsp server
     nil # nix lsp server
-    rnix-lsp # nix lsp
     clang-tools # c/c++ lsp server
     rust-analyzer # rust analyzer
 

user/kakoune/kak-lsp.toml

@@ -120,8 +120,8 @@ command = "nimlsp"
 
 [language.nix]
 filetypes = ["nix"]
+command = "nil"
 roots = ["flake.nix", "shell.nix", ".git"]
-command = "rnix-lsp"
 [language.nix.settings.nil]
 formatting.command = [ "nixpkgs-fmt" ]