home: vim: lspconfig: remove 'rnix-lsp'

It's been abandoned, `nil` is a better language server nowadays.

modules/home/vim/plugin/settings/lspconfig.lua

@@ -45,13 +45,6 @@ if utils.is_executable("nil") then
     })
 end
 
-if utils.is_executable("rnix-lsp") then
-    lspconfig.rnix.setup({
-        capabilities = capabilities,
-        on_attach = lsp.on_attach,
-    })
-end
-
 -- Python
 if utils.is_executable("pyright") then
     lspconfig.pyright.setup({

modules/home/vim/plugin/settings/null-ls.lua

@@ -31,11 +31,9 @@ null_ls.register({
 -- Nix
 null_ls.register({
     null_ls.builtins.formatting.nixpkgs_fmt.with({
-        -- Only used if available, but prefer rnix if available
+        -- Only used if available, but prefer LSP if available
         condition = function()
-            return utils.is_executable("nixpkgs-fmt")
-                and not utils.is_executable("rnix-lsp")
-                and not utils.is_executable("nil")
+            return utils.is_executable("nixpkgs-fmt") and not utils.is_executable("nil")
         end,
     }),
 })