flake: add explicit 'systems' input

flake.lock

@@ -86,7 +86,9 @@
     },
     "futils": {
       "inputs": {
-        "systems": "systems"
+        "systems": [
+          "systems"
+        ]
       },
       "locked": {
         "lastModified": 1701680307,
@@ -214,7 +216,8 @@
         "home-manager": "home-manager",
         "nixpkgs": "nixpkgs",
         "nur": "nur",
-        "pre-commit-hooks": "pre-commit-hooks"
+        "pre-commit-hooks": "pre-commit-hooks",
+        "systems": "systems"
       }
     },
     "systems": {
@@ -228,6 +231,7 @@
       },
       "original": {
         "owner": "nix-systems",
+        "ref": "main",
         "repo": "default",
         "type": "github"
       }

flake.nix

@@ -27,6 +27,9 @@
       owner = "numtide";
       repo = "flake-utils";
       ref = "main";
+      inputs = {
+        systems.follows = "systems";
+      };
     };
 
     home-manager = {
@@ -64,6 +67,13 @@
         nixpkgs-stable.follows = "nixpkgs";
       };
     };
+
+    systems = {
+      type = "github";
+      owner = "nix-systems";
+      repo = "default";
+      ref = "main";
+    };
   };
 
   # Can't eta-reduce a flake outputs...