Add nix flake for dev shell (#30967)

To try it you need **nix** installed `nix-daemon ` running and your user
has to be member of the **nix-users** group. Or use NixOS.

then by just:
```sh
nix develop -c $SHELL
```
a dedicated development environment with all needed packages will be
created.

(cherry picked from commit de6f0488a67ad65bd2ac40356b08a78a365414cd)

flake.nix

@@ -0,0 +1,37 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+  outputs =
+    { nixpkgs, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            # generic
+            git
+            git-lfs
+            gnumake
+            gnused
+            gnutar
+            gzip
+
+            # frontend
+            nodejs_20
+
+            # linting
+            python312
+            poetry
+
+            # backend
+            go_1_22
+          ];
+        };
+      }
+    );
+}