refactor: replace nixify with flake-utils and rust-overlay in flake.nix

flake.nix

@@ -1,67 +1,54 @@
 {
-  inputs.nixify.url = "github:rvolosatovs/nixify";
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
 
   outputs =
-    { nixify, ... }:
-    with nixify.lib;
-    rust.mkFlake {
-      src = ./.;
-
-      withDevShells =
-        {
-          devShells,
-          pkgs,
-          ...
-        }:
-        extendDerivations {
-          env.LD_LIBRARY_PATH = "$LD_LIBRARY_PATH:${
-            with pkgs;
-            pkgs.lib.makeLibraryPath [
-              xorg.libX11
-              xorg.libXcursor
-              xorg.libXi
-              libxkbcommon
-              xorg.libxcb
-              pkgs.vulkan-loader
-              pkgs.glfw
-            ]
-          }";
-          buildInputs = with pkgs; [
-            pkgs.pkg-config
-            pkgs.alsa-lib.dev
-            pkgs.udev.dev
-          ];
-        } devShells;
-
-      buildOverrides =
-        {
-          pkgs,
-          pkgsCross ? pkgs,
-          ...
-        }:
-        {
-          buildInputs ? [ ],
-          nativeBuildInputs ? [ ],
-          depsBuildBuild ? [ ],
-          ...
-        }:
-        with pkgs.lib;
-        {
-          nativeBuildInputs =
-            nativeBuildInputs
-            ++ optional (pkgs.stdenv.hostPlatform.isLinux) [ pkgs.pkg-config ];
-
+    {
+      nixpkgs,
+      flake-utils,
+      rust-overlay,
+      ...
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        overlays = [ (import rust-overlay) ];
+        pkgs = import nixpkgs { inherit system overlays; };
+        runtimeLibs = with pkgs; [
+          libx11
+          libxcursor
+          libxi
+          libxkbcommon
+          libxcb
+          vulkan-loader
+          glfw
+        ];
+      in
+      {
+        devShells.default = pkgs.mkShell {
           buildInputs =
-            buildInputs
-            ++ optional pkgs.stdenv.hostPlatform.isDarwin pkgs.libiconv
-            ++ optional (pkgs.stdenv.hostPlatform.isLinux) [
-              pkgs.alsa-lib.dev
-              pkgs.udev.dev
-            ];
+            with pkgs;
+            [
+              (rust-bin.stable.latest.default.override {
+                extensions = [
+                  "rust-src"
+                  "rust-analyzer"
+                ];
+              })
+              pkg-config
+              alsa-lib.dev
+              udev.dev
+            ]
+            ++ runtimeLibs;
 
-          depsBuildBuild =
-            depsBuildBuild
-            ++ optional pkgsCross.stdenv.hostPlatform.isDarwin pkgsCross.xcbuild.xcrun;
+          LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath runtimeLibs;
         };
-    };
+      }
+    );
 }