feat(extras): lang/zig (#4437)

## Description

A fresh and minimalist take on #1750.
It only adds what is maintainable (has activity in the past year at
least).

## Related Issue(s)

Closes #1750.


## Checklist

- [x] I've read the
[CONTRIBUTING](https://github.com/LazyVim/LazyVim/blob/main/CONTRIBUTING.md)
guidelines.

lua/lazyvim/plugins/extras/lang/zig.lua

@@ -0,0 +1,32 @@
+return {
+  recommended = function()
+    return LazyVim.extras.wants({
+      ft = { "zig", "zir" },
+      root = { "zls.json", "build.zig" },
+    })
+  end,
+  {
+    "nvim-treesitter/nvim-treesitter",
+    opts = { ensure_installed = { "zig" } },
+  },
+  {
+    "neovim/nvim-lspconfig",
+    opts = {
+      servers = {
+        zls = {},
+      },
+    },
+  },
+  {
+    "nvim-neotest/neotest",
+    optional = true,
+    dependencies = {
+      "lawrence-laz/neotest-zig",
+    },
+    opts = {
+      adapters = {
+        ["neotest-zig"] = {},
+      },
+    },
+  },
+}