Fixed flake check errors

Also constrained support to just x86_64-linux, I ran into issues with
aarch64-linux but I don't have a usecase for that anyway.

flake.lock

@@ -10,9 +10,8 @@
         "type": "github"
       },
       "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
+        "id": "flake-utils",
+        "type": "indirect"
       }
     },
     "nixpkgs": {

flake.nix

@@ -3,17 +3,18 @@
 
   inputs = {
     nixpkgs.url = github:NixOS/nixpkgs/nixos-unstable;
-    flake-utils.url = github:numtide/flake-utils;
   };
 
   outputs = {
     self,
     nixpkgs,
     flake-utils,
-  }:
-    with flake-utils.lib;
-      eachSystem allSystems (system: let
-        pkgs = nixpkgs.legacyPackages.${system};
+  }: let
+    pkgs = import nixpkgs {
+      inherit system;
+    };
+    lib = pkgs.lib;
+    system = "x86_64-linux";
     nerdfonts-hack = pkgs.nerdfonts.override {
       fonts = ["Hack"];
     };
@@ -24,9 +25,10 @@
     # Create definitions like \def\email{$EMAIL}
     # Each \email command in the tex document will be populated by an EMAIL
     # variable (can be set as an environment variable)
-        texvars = toString (pkgs.lib.concatMapStrings (x: ''\def\${x}{${"$" + pkgs.lib.toUpper x}}'') vars);
-      in rec {
-        packages = {
+    texvars = toString (lib.concatMapStrings (x: ''\def\${x}{${"$" + lib.toUpper x}}'') vars);
+  in {
+    packages.${system} = {
+      # inherit system;
       alejandro-resume = pkgs.stdenvNoCC.mkDerivation rec {
         name = "alejandro-resume";
         src = self;
@@ -36,7 +38,7 @@
           #!/usr/bin/env bash
 
           prefix=${builtins.placeholder "out"}
-              export PATH="${pkgs.lib.makeBinPath propogatedBuildInputs}";
+          export PATH="${lib.makeBinPath propogatedBuildInputs}";
           DEBUG=false
           DIR=$(mktemp -d)
           RES=$(pwd)/alejandro_resume.pdf
@@ -94,10 +96,10 @@
           chmod u+x $out/bin/alejandro-resume
         '';
       };
+      default = self.packages.${system}.alejandro-resume;
     };
-        defaultPackage = packages.alejandro-resume;
 
-        devShells = {
+    devShells.${system} = {
       default = pkgs.mkShell {
         name = "default";
         buildInputs = with pkgs; [
@@ -120,5 +122,5 @@
         '';
       };
     };
-      });
+  };
 }