chore: remove redundant flake-utils dependency; add nix-systems

Removes the redundant flake-utils dependency, and replaces
multi-system handling logic with a minimal function (zero deps!) that
supports [nix-systems](https://github.com/nix-systems). This gets rid of
the unnecessary flake-utils dependency.

Also see:
  * https://ayats.org/blog/no-flake-utils

2 files changed, 19 insertions, 35 deletions

diff --git a/flake.lock b/flake.lock
index 5df3c816..734f9b02 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,23 +1,5 @@
 {
   "nodes": {
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1694529238,
-        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1699906975,
@@ -35,8 +17,8 @@
     },
     "root": {
       "inputs": {
-        "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "systems": "systems"
       }
     },
     "systems": {
diff --git a/flake.nix b/flake.nix
index 62dcb861..04681a1c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,20 +2,22 @@
   description = "Quickstart configurations for the Nvim LSP client";
 
   inputs.nixpkgs.url = "github:NixOS/nixpkgs";
-  inputs.flake-utils.url = "github:numtide/flake-utils";
+  inputs.systems.url = "github:nix-systems/default";
 
-  outputs = { self, nixpkgs, flake-utils }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let pkgs = nixpkgs.legacyPackages.${system}; in
-      rec {
-        devShell = pkgs.mkShell {
-          buildInputs = [
-            pkgs.stylua
-            pkgs.luaPackages.luacheck
-            pkgs.luajitPackages.vusted
-            pkgs.selene
-          ];
-        };
-      }
-    );
+  outputs = { self, nixpkgs, systems }: let
+    supportedSystems = nixpkgs.lib.genAttrs (import systems);
+    forEachSystem = function: supportedSystems (system:
+        function nixpkgs.legacyPackages.${system});
+  in {
+   devShells = forEachSystem (pkgs: {
+      default = pkgs.mkShell {
+        packages = [
+          pkgs.stylua
+          pkgs.luaPackages.luacheck
+          pkgs.luajitPackages.vusted
+          pkgs.selene
+        ];
+      };
+    });
+  };
 }