chore: Add nix development environment (#6314)

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

flake.lock

@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1769461804,
+        "narHash": "sha256-6h5sROT/3CTHvzPy9koKBmoCa2eJKh4fzQK8eYFEgl8=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "b579d443b37c9c5373044201ea77604e37e748c8",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}